Awesome to see that drive running!! Great work! I did all my most involved 1541 troubleshooting on it when I got it. I powered it on several times AND I tried 2 different disks! :-) Then I put it on the shelf. ;-) Considering where that stuff came from, I am impressed you are getting these running! Great work as always!!!
Attaching a C64 and querying the command channel (@ with FASTLOAD) is a diagnostic that I have not seen anybody consider. If it succeeds, it tells a lot: CPU, ROM, RAM, one of the two VIAs, and +5VDC are good. Then swapping the VIAs would be the very next step to see if the fault follows. (They are typically socketed.)
My mind is blown. I used to repair these things at a school board. I might of repaired 6 to 10 1541, c64s, 1701 a day. Very fast high volume repair shop. I can still hear the diagnostic audio test playing in my head. Thanks for the memories. Wow. I can't believe all the old hardware that didn't make it to landfill. Imagine a time where computers that never knew what a virus was.
4 years later this video is still valuable! That tidbit about the 74123 can interfere with reading disks might be what I needed to hear. Thanks Adrian!
My first repair! When age 9 Mom got me one of those cheap 30 watt Radio Shack soldering irons and a roll of good ole lead solder. Went to use my C64 and the magic smoke came out off the 1541 , I opened it up and managed to break the fuse holder then find the problem, the bridge rectifier had a burned hole in it. So Mom took me back to RadioShack and bought a new bridge rectifier and a fuse holder. Working unsupervised age 9 I had the drive running by dinner! - That set my path! By 12 I had my Novice ham license and was searching for the next thing I could try to fix.
Adrian, I subscribe to a few different channels that are informative. I learn from them all, including yours. One aspect of yours that stands out, however, is that you take time to take us viewers all the way through the process: your thinking, testing, failing, trying another angle, ultimately leading to success. To me, it feels like I'm there with you on what you're working on. It's a subtle thing, but it is really huge as well. Thank you!
Hehe ... exact same thing happened to me a couple of days ago ... was also going to make a video on it :) was looking at the same schematics ... you should have seen my wife’s face as I was running through the house with the disk drive and a trail of magic smoke behind me :)
I love watching your videos. Takes me back to my childhood with my c64 and 1541 which I still have in my closet. I need to get it out to show my kids a real computer.
This video was awesome! Specifically, in the "modern era" of PCs, who would have have thought you at to have a cpu running things like a disk drive! Today, disk (floppy) drives are all most forgotten about and redundant. Once again many thanks for an excellent video.
I had a dead 6502 in my original 1541 drive too. It was very easy to fault find as it got very VERY hot! I also replaced the MOS branded logic chips and electrolytic capacitors while it was apart. My drive had been extensively modded by a teenage me. I fitted an 80mm fan to the top of the lid (complete with holes melted through by a soldering iron) and also drive select toggle switches on the back with two red LEDs on the front to show the drive number. It's now hooked up to my PC via a ZoomFloppy.
As for the drinking game, probably not. I can't really get drunk. All I get is the hangover so it's kind of a no go. As for that jumper though. The Alps heads are wound a little more thereby having a few more joules to impart to the disk. If it writes to heavily, it can create hard bad blocks on the floppies. Considering how rare those are these days it could create some problems for you when you go to format a diskette you've used for something else in that drive. Total pain where you sit because then you have to low level format it and pray it works to clear the bad blocks, which it sometimes can (note to future selves for floppies that are otherwise trash). That said, I have a lot of love for old machines. Between you and Curious Mark I've learned a lot and even used it. There aren't words for how grateful I am for the knowledge. I've pulled 5 machines from storage and restored them because of you guys. Thanks man, and if you ever make it to Spokane I'd like to hang out for awhile so feel free to message me if that sounds like a plan to you too.
Great video Adrian. Nice camera work and editing. I used to work on electronic repairs for a school board. We had many hundreds Vic20/C64 and even Amigas. I enjoy the way you describe what you are doing while you are troubleshooting.
Wonderful restoration job on that 1541, I never get enough of seeing Commodore devices being brought back to life, those are the only computers I grew up knowing aside from the Apple II.
Awesome stuff!! Doing basic repair on 1541/1571 drives was how I got started as a kid fixing computers, and basic electronics in the late 80's, and usually it involved cleaning/lubing the drives, going to my local Radio Shack/Computer store for belts, replacing a cap, or sometimes simply on the lever drives just putting the pin back into place with some hot snot so it would not pop out again, and it would open/close proper. However the last drive I repaired was almost 25 years ago now, so honestly thanks for memories. 👍👍
Thanks! You helped fix my drive. I had exactly the same symptoms as you did and walked through with you step by step with my oscilloscope, to discover, I too had a faulty 6502. My drive is now working!
Man these videos take me back to my early computer days. My first machine was a C=128 and I ordered a 1571 and a dataset with the package from Sears (My only credit card!) Later I picked up an old c64 for personal use as I couldn't get access with 2 kids in high school using the 128 all the time. I even had a plus4 when the price on them dropped to 20 bucks. Even went so far as to buy a luggable from a fellow user who went to PC. I sold that several years ago for enough money to buy a new laptop. Now I sort of wish I still had it but there are many things in life that I feel that way about. Thanks for the trip back in time!
Head alignment is the most important aspect of 1541 repair. I’d love to see you do that. You already have the scope, you just need the analog alignment disk.
Bad sector copy protection played hell with 1541s because they would run over to track 0 and bang the heads against the stop when they hit a bad sector. I was an Atari guy but had coworkers with 64's. It cracked me up when the 1541 would suddenly step over and go "ack ack ack ack ack ack ...". Not nice on the old stepper motor mechanical head positioning systems.
@Mr Guru Cool, link for the disks? I haven't needed one myself because I've just aligned drives (like the trs-80) with a known good disk. Also, with the apple ii, the disk alignment stuff is pretty easy as well (stephen buggie has a video on youtube). I've never had any reason to do it with a c64 though.
@Mr Guru Yup. I don't have any alignment issues personally, but it would be handy to have a disk while they're still around. Though, honestly I wouldn't put much effort into fixing a drive since it's a dead medium and they aren't making more. Better off spending the money on a pi1541 or sd2iec.
Mr Guru As a former Commodore bench tech, I can tell you about 10% of 1541 repairs were due to head alignment issues. We would score and epoxy the stepper motor spindle after alignment to keep it there.
Great that you got this little guy working again. They really are workhorse drives. I have some that say in a Storage on Tucson For 18 years in the heat, and just requires a bit of cleaning and lube to be fully functional again.
This video is very Serendipitous for me, as I'm digging out some old c64 disk drives to give them away, and I'm finding out that many are having the exact same issue. Thank You so much!
I took apart my own 1541 out of curiosity. It works, but I never took it apart. The chip pins are extremely rusty, there's a lot of shoddy repair work. Might have to do some proper maintenance. Thanks for the video!
I had that exact drive model from 1986 to like 1989. That noise you‘re complaining about was there from the first day to the day the drive broke. It was never an issue.
I've bought a couple drives with read errors which only needed lubricating and cleaning the head. Paid like a third for the 2 drives of what a single working drive was sold for. These ones that seem stuck on etc. can cost a bit more to fix when you have to source chips for it
I repaired mine by replacing the drive nechanism. When i was in poland over the summer, i got a drive locally (25 k) on a bike and brought it back to Canada in my luggage . It worked, and surprisingly it was an ALPS unit that wasn't shot. Rare. The german built replacement also had no screws in it!
I had multiple 1541 drives and all are Alps -- so I've had good luck with them being reliable. I must say a 1541 is a boat of a boat anchor so it's good your luggage didn't go overweight!
@@adriansdigitalbasement I was thinking of discarding the breadbox in Poland and just shipping the drive, but I brought almost nothing with me for vacation so I had lots of room. Even brought back a few PCs ;) Someone actually bought the 220v case off me, so that recouped some of my expenditure. As for ALPS, the site I went to to get notes had mentioned that the ALPS units are pretty much unreliable. Good work again, I can see you're changing your tone in the vids, I'm thinking of doing the same ;)
Great seeing these deep dives with the scope. Fixed one of these the other day where the motor wouldn't spin. Turned out to be a bad inverter which seems to be a common issue.
Tants my nemesis! Used a lot in 70’s & 80’s audio equipment, sometimes used for their audio characteristics and low ESR, but used a lot just for their size. I must have changed more Tants "Just in case” than any other componant. Ive obviously canged more eletrolytics but they give away their faults in a more obvious way. Yes a dead tant is in you face but they go from good to bad in micro seconds rather than slowly over time like electrolytic’s. And if a piece of kit you’ve just worked on, goes pop, on a gig or in a studio sesion then say goodbye to your reputation !
Hi, one trick that I use for the oscilloscope is to connect the ground connection from the test point on the lower right corner to the board ground with a jumper cable and remove the little wire that is always in the way!
Those ground wires on scope probes often break. On my Tektronix scope I have had to fix them several times. The wire breaks inside the insulation due to flexing. You can tell if it's broken if you gently pull the two ends apart. If the insulation stretches, it's broken.
you are a great inspiration, i have reasonable electronic knowledge and just purchased a C64 with disk drive, no PSU and not knowing if any of it works...fingers crossed will be an interesting project
Took me back to my old C64 / 1541 combo. It was a big upgrade from an old Sinclair ZX81 as at the time it was the closest thing I could get that felt like a real computer and not a glorified calculator. Might have to have a rummage in the loft, never know it might still be up there from when I switched to an A1200. Love your detailed explanation of how it all is supposed to work, I got into an electronics repair job but at the time it was all transistors and valves as we were still using 1960s/70's RADAR technology at the time.
As a retired EE with 50 years of oscilloscope use I can say that I have had several scope probe ground clips fail. Other test leads as well. Right where the hard rubber for the strain relief ends is common. Grab both the metal ends and you may be able to pull the lead apart and see where the metal failed. It can be very frustrating figuring out what's going on, especially when its not completely broken, just intermittent.
Great video. Although I am not very knowledgeable about electronics, I enjoy watching you fix computers and Commodore 1541. Keep up the excellent videos!
I guessed the problem with one look at the board (aside from the jumper and the bad socket). Just looking at the CPU you could tell it did not match the rest of the board and had been recently transplanted. Still a great vid on 1541 repair thanks.
I have plenty of experience about test leads and ground leads breaking. Frequent bends does that to even the highly flexible vires. What I have found useful in detecting the location of thew break is to have the meter on beep and then grab different short sections of the cable between fingers and push, sort of trying to shorten the wire. If I am at the break point, it typically makes contact as indicated by a beep.. It is easier to do with rubber or silicone insulated wires, because they are softer. Often I can also detect an extra flexible spot, where the copper is broken. Maybe a light pull and bend reveals the break in those situations.. Then I just cut, apply silicone sleeving (or heat shrink, peel a short length of the ends, solder the wires and pull the sleeving on. Considerably more cumbersome when the break is at the very end or even inside the molded strain relief. But that is another story.
22:31 My station also makes noise when the disk is turned, and it's the platter at the top that makes the noise. This part has worn out quite a bit and even grease doesn't help. I don't know if this plate works on the "clutch" principle, but I noticed that the axle does not always rotate. Programs load correctly.
Ground lead is easy to fix, just cut the plastic away from the copper plated steel spring, and solder a new wire onto it, then cover with some heatshrink sleeving. Use extra flexible cable, and you can make a slightly longer lead, though you will lose some signal integrity on the longer lead, but will make it more convenient to probe multiple places instead of the extra lead you added to the ground lead.
Back in the day I got a new C64 with a 1541, I new zero about computers. I bought a tape drive from a friend and was using that a while til one day he came over and was like, wth are you doing, using a tape drive, you have a disk drive! I had no clue what it was even for. LOL. Those were the days...
I remember in my teens fixing my 1541. It was reporting I/O errors I guess as I had to change the two LMxxxx chips that make up the head amplifier. They were listed as VCR head amplifiers, but I guess one magnetic head is like another. Thanks for the video.
Your videos are gold. I have 2 C64 along 2 drives who both act not normal at all. I'm learning so much on what to probe and what might be the top issues. The one C64 is my very first computer, I got when I was 8 years old, 29 years ago. It means a lot to me. The second I bought a year ago, just to be able to find what's wrong with mine, but sadly it has issues as well and this makes it all more complicated. I'm not willing to buy another set. :)
@@gregfleury1705 I am in complete agreement with everything you said, but i would like to add that Adrian seems like a genuinely nice guy; e.g. i have never heard him utter a harsh word at anyone, at worst he may cuss at some recalcitrant piece of equipment ;)
Great stuff, love seeing these 1541 refurbs. My red light of death issue lat year was the CPU being held in Reset. Turned out to be the UA1 IC. Thanks to @GadgetUK164 for pointing me in the right direction.
Nice repair, it might help me diagnose my drive that has similar issues. I think that pcb was swapped out because it didnt match the case mods and the jumper was set for a different drive.
5:33 Random needless tip: An old electric toothbrush is amazing for cleaning flux. It's like a point and shoot ultrasonic cleaner. Nice but not an essential for back of the board stuff. It does make tight access areas on a component side much more accessible. With prototypes small enough to fit in my jewelry-type ultrasonic cleaner filled with 90% iso, the combo can clean anything in under 1 minute :-)
That is a great tip!! Annoying is I had one that had a bad battery so I sent it off to ewaste. But it held enough charge to do cleaning like that. Doh!!
@@adriansdigitalbasement Go to Dollar General, Family Dollar, etc.. and look for a brand called Dr. Fresh, they have electric toothbrushes for $1 - $2.50, I got the idea after my girlfriend bought one to try, and save us some money, and they even come with a AA battery installed, meaning nothing to have to worry about recharging, and while not as great as some other brands for the price they work, and get the job done of both cleaning your teeth, and other things you would use a toothbrush for like electronics. lol!
@@adriansdigitalbasement I've replaced the battery in mine about 6 times now and it's still going strong 15 years later!!! Look for battery replacement videos on YT. It's possible on most brands/models, just requires a bit of desoldering and soldering - well within your skill set :)
Hi again, I also remember that my "toaster" drive (because the way it pops out the disk) the plastic rails for the eject broke, you have to be careful with those, do not pop it hard keep pressure to move slowly the latch, and I had replaced the rails with brass inserts to repair the drive eject mechanism.
Another name I've heard of for those C-clips is "Jesus clips". So called because when they go flying across the room when taking them off, that's how you express your disdain.
28:50: Is that a different drive at the end? I don't see the square cutouts under the LED light on the lower housing that you showed in the beginning of the video. Did you change the lower housing plastic?
BTW you might try some MMO for the drive. Marvel Mystery Oil is good for old crusty stuff like that or Extreme Pressure applications ( I have used it on my air tools for decades now & haven't had a failure yet. ) Also if you put a drop on that old troublesome crusty spot you will find that some of it evaporates away leaving a nice controlled amount of lubrication & protection. Also, prior to that, 1000 grit black automotive sandpaper is really handy for cleaning and polishing off those parts. Gives you great control on the pool table, also, if you use it on the leather end of your cue prior to chalking.
Enjoying your videos. I like to repair electronic equipment, and would appreciate a video or two with more in depth use and explanation of the oscilloscope for fault finding. My knowledge on their use is pretty shallow but I really want to learn! Any help would be appreciated 👍
Congratulations on the repair. When I restore old gear with tantalums, I replace all of them because they tend to burn a little too often and when one has failed the rest are likely on the threshold. There are I think 12 undocumented opcodes in at least some versions of the 6502B that will stall the CPU so unless you're watching with an analyzer from /RESET going high it's possible to see what you're seeing here and still have a good CPU if the ROM is bad. In the 80s these opcodes were commonly called KIL or HCF (halt, catch fire).
Happens plenty, good little habit you can do is to check the probe calibration.. Should be a pair of clip on points on the CRO which output a square wave 5Vp-p signal, used to get your capacitance adjustment right.. also will make it very obvious when ground wire is dud,,
I think you can safely lift the head counter part all the way up. At least you can on 1541-II. I was anxious about it too, but once I lifted it up, it seemed like something it was designed to allow.
One day we'll get to hear Adrian say "Bringing out my ZIF 1514" Can't help you with the scope probe. My 40 year old B&K 1465 came with it's original probes and the ground clips still work on that. Probably just the copper inside died.
It's not different than my TS100 soldering iron which recently had the power cable fail in a similar one. Both are soft silicone cables -- so maybe there is a bad manufacturer in China....
Just loves your videos, to bad they are consumed so fast hehe more more :D you doing a great job, loving intro in real retro style.. keep up the good work, and real nice way of telling and showing how to handle retro check and repairs.
Not too surprised about the probe issue. Thin cable constantly pivoting at the point where the strain relief ends is a really common killer of headphone and cheap USB cables.
Playing board games with friends so could only skim through it without sound, but on the top right of the pcb is a tantalum cap on the 12v rail that exploded on mine. Dunno if you replaced that one but think it might be wise to do so. Old tantalum caps and 12v tails don’t play nice together.
One of the traps with the original 650x's to keep in mind, though, is that if they execute certain undefined instruction codes they go off to Neverland until a reset, so they may seem unresponsive when it is really a case of GIGO.
Indeed.... I read that in the "C" versions they changed it so it would just run a "NOP" when you issued any illegal instruction to prevent that locking up.
Nice work! The ROMs are always the first thing I check (after voltages ofc), especially on longboards. One of the ROM chips are very close to the rectifiers and that is often bad. One of the few bad 6502's I found was actually also in a drive (SX64 internal).
Definitely had the scope ground leads fail before. On some scopes, you can provide the ground using a banana plug on the scope. It isn’t as accurate as the per channel grounds but it is probably good enough for what you are doing here and makes scoping different parts of the board even easier
6502 could have been zapped caused by someone not using a static strap. Glad you found the problem. Interesting now most of the chips have yellow dots. When you first started I thought to myself something is not like the others. 6502 was black and clean so after replacing the cap, I would have swapped out the 6502 as it seemed like a likely suspect. If not working still then on to the oscilloscope. What settings are you using for the Oscope? Thanks again for showing this and Great work!
I've had my share of trouble fixing that typical ALPS scratching noise from the spindle setup and got a result more or less like you got with silicone grease. I 'm very certain that in my earliest memories from the 80s those ALPS drives were actually pretty quiet back then. Looking at other drives like the Mitsumi one , I think that spindle shaft should barely move at all. The plastic part locking on to the disc should pretty much move freely and not turn the shaft that holds it in place. I believe silicone grease is too sticky and causes the spindle shaft to turn and scratch.
Your Deoxit drinking game reminds me, it's been forever since I've seen Neil at Retro Man Cave use his baking powder for fluffy muffins to clean a case. I've had success with both baking powder and Deoxit too, even if I can't find the same type here in the States.
Thanks for another great video, I always enjoy watching them! Regarding the dead CPU, I do not know much about them but if a ROM/RAM was bad, would the CPU still show activity - while trying to access the ROM - or would it just try once and then give up?
Awesome to see that drive running!! Great work! I did all my most involved 1541 troubleshooting on it when I got it. I powered it on several times AND I tried 2 different disks! :-) Then I put it on the shelf. ;-) Considering where that stuff came from, I am impressed you are getting these running! Great work as always!!!
Attaching a C64 and querying the command channel (@ with FASTLOAD) is a diagnostic that I have not seen anybody consider. If it succeeds, it tells a lot: CPU, ROM, RAM, one of the two VIAs, and +5VDC are good. Then swapping the VIAs would be the very next step to see if the fault follows. (They are typically socketed.)
My mind is blown. I used to repair these things at a school board. I might of repaired 6 to 10 1541, c64s, 1701 a day. Very fast high volume repair shop. I can still hear the diagnostic audio test playing in my head. Thanks for the memories. Wow. I can't believe all the old hardware that didn't make it to landfill. Imagine a time where computers that never knew what a virus was.
You should have had a shot of you putting the chip in the bad chip box. It's tradition!
Big Car
I am so happy you’re around, to tell other people how to do things. We need supervision from leaders like you.
Thank you!
4 years later this video is still valuable! That tidbit about the 74123 can interfere with reading disks might be what I needed to hear. Thanks Adrian!
"If you're doing the drinking game, it's time to take another drink!"
Oh no guys! He figured us out!
ive had arians videos playing in the background... its now 3am local time and I cannot feel my face.
DeOxiT... slam!
My first repair! When age 9 Mom got me one of those cheap 30 watt Radio Shack soldering irons and a roll of good ole lead solder. Went to use my C64 and the magic smoke came out off the 1541 , I opened it up and managed to break the fuse holder then find the problem, the bridge rectifier had a burned hole in it. So Mom took me back to RadioShack and bought a new bridge rectifier and a fuse holder. Working unsupervised age 9 I had the drive running by dinner! - That set my path! By 12 I had my Novice ham license and was searching for the next thing I could try to fix.
Adrian, I subscribe to a few different channels that are informative. I learn from them all, including yours. One aspect of yours that stands out, however, is that you take time to take us viewers all the way through the process: your thinking, testing, failing, trying another angle, ultimately leading to success. To me, it feels like I'm there with you on what you're working on. It's a subtle thing, but it is really huge as well. Thank you!
Hehe ... exact same thing happened to me a couple of days ago ... was also going to make a video on it :) was looking at the same schematics ... you should have seen my wife’s face as I was running through the house with the disk drive and a trail of magic smoke behind me :)
Oh god i have a minor picture in my head, just with 2 doomguys. xD
I thought of you when the tantalum went bad. Hey that’s RetroSpector’s trick! ;-)
And therefore she gave you a new "THE C64" for birthday?! :-) :-)
I love watching your videos. Takes me back to my childhood with my c64 and 1541 which I still have in my closet. I need to get it out to show my kids a real computer.
This video was awesome! Specifically, in the "modern era" of PCs, who would have have thought you at to have a cpu running things like a disk drive! Today, disk (floppy) drives are all most forgotten about and redundant. Once again many thanks for an excellent video.
I had a dead 6502 in my original 1541 drive too. It was very easy to fault find as it got very VERY hot! I also replaced the MOS branded logic chips and electrolytic capacitors while it was apart. My drive had been extensively modded by a teenage me. I fitted an 80mm fan to the top of the lid (complete with holes melted through by a soldering iron) and also drive select toggle switches on the back with two red LEDs on the front to show the drive number. It's now hooked up to my PC via a ZoomFloppy.
As for the drinking game, probably not. I can't really get drunk. All I get is the hangover so it's kind of a no go. As for that jumper though. The Alps heads are wound a little more thereby having a few more joules to impart to the disk. If it writes to heavily, it can create hard bad blocks on the floppies. Considering how rare those are these days it could create some problems for you when you go to format a diskette you've used for something else in that drive. Total pain where you sit because then you have to low level format it and pray it works to clear the bad blocks, which it sometimes can (note to future selves for floppies that are otherwise trash). That said, I have a lot of love for old machines. Between you and Curious Mark I've learned a lot and even used it. There aren't words for how grateful I am for the knowledge. I've pulled 5 machines from storage and restored them because of you guys. Thanks man, and if you ever make it to Spokane I'd like to hang out for awhile so feel free to message me if that sounds like a plan to you too.
I have 2 old 1541 drives coming my way, so watching this gives me some help at know what to look for. Thanks.
Great video Adrian. Nice camera work and editing. I used to work on electronic repairs for a school board. We had many hundreds Vic20/C64 and even Amigas. I enjoy the way you describe what you are doing while you are troubleshooting.
@ Adrian's Digital Basement
I just noticed... You're currently at 64K subscribers. LOL!
Love repairing videos and how you explain the thought process! Thank you Adrian and keep up the great content!
Wonderful restoration job on that 1541, I never get enough of seeing Commodore devices being brought back to life, those are the only computers I grew up knowing aside from the Apple II.
Awesome stuff!! Doing basic repair on 1541/1571 drives was how I got started as a kid fixing computers, and basic electronics in the late 80's, and usually it involved cleaning/lubing the drives, going to my local Radio Shack/Computer store for belts, replacing a cap, or sometimes simply on the lever drives just putting the pin back into place with some hot snot so it would not pop out again, and it would open/close proper. However the last drive I repaired was almost 25 years ago now, so honestly thanks for memories. 👍👍
Thanks! You helped fix my drive. I had exactly the same symptoms as you did and walked through with you step by step with my oscilloscope, to discover, I too had a faulty 6502. My drive is now working!
Man these videos take me back to my early computer days. My first machine was a C=128 and I ordered a 1571 and a dataset with the package from Sears (My only credit card!) Later I picked up an old c64 for personal use as I couldn't get access with 2 kids in high school using the 128 all the time. I even had a plus4 when the price on them dropped to 20 bucks. Even went so far as to buy a luggable from a fellow user who went to PC. I sold that several years ago for enough money to buy a new laptop. Now I sort of wish I still had it but there are many things in life that I feel that way about. Thanks for the trip back in time!
Head alignment is the most important aspect of 1541 repair. I’d love to see you do that. You already have the scope, you just need the analog alignment disk.
Bad sector copy protection played hell with 1541s because they would run over to track 0 and bang the heads against the stop when they hit a bad sector. I was an Atari guy but had coworkers with 64's. It cracked me up when the 1541 would suddenly step over and go "ack ack ack ack ack ack ...". Not nice on the old stepper motor mechanical head positioning systems.
finding those alignment disks is difficult. those who have them are hoarding them. 😁
@Mr Guru Cool, link for the disks? I haven't needed one myself because I've just aligned drives (like the trs-80) with a known good disk. Also, with the apple ii, the disk alignment stuff is pretty easy as well (stephen buggie has a video on youtube). I've never had any reason to do it with a c64 though.
@Mr Guru Yup. I don't have any alignment issues personally, but it would be handy to have a disk while they're still around. Though, honestly I wouldn't put much effort into fixing a drive since it's a dead medium and they aren't making more. Better off spending the money on a pi1541 or sd2iec.
Mr Guru As a former Commodore bench tech, I can tell you about 10% of 1541 repairs were due to head alignment issues. We would score and epoxy the stepper motor spindle after alignment to keep it there.
Fantastic. I could watch you troubleshoot stuff all day.
Who the heck would ever dislike videos like this. Seriously, you know what to expect before watching, and Adrian never disappoints.
Probably a Speccy user.
had a pile of those in my shop. started scraping them out and they worked. Never knew anybody was interested in using them again.
Great that you got this little guy working again. They really are workhorse drives. I have some that say in a Storage on Tucson For 18 years in the heat, and just requires a bit of cleaning and lube to be fully functional again.
I love to watch a successful repair. Well done Adrian.
This video is very Serendipitous for me, as I'm digging out some old c64 disk drives to give them away, and I'm finding out that many are having the exact same issue. Thank You so much!
I find your videos fascinating, the fault finding is great. Another good to go product!
I took apart my own 1541 out of curiosity. It works, but I never took it apart. The chip pins are extremely rusty, there's a lot of shoddy repair work. Might have to do some proper maintenance. Thanks for the video!
I had that exact drive model from 1986 to like 1989. That noise you‘re complaining about was there from the first day to the day the drive broke. It was never an issue.
The best video for fixing a 1541 online ! Thanks for taking the time to create and share this video !!
Thumbs Up! Excellent video. I think this is the first video where I have seen someone take apart the clamping mechanism. Very helpful. Thanks!
I've bought a couple drives with read errors which only needed lubricating and cleaning the head. Paid like a third for the 2 drives of what a single working drive was sold for. These ones that seem stuck on etc. can cost a bit more to fix when you have to source chips for it
I repaired mine by replacing the drive nechanism. When i was in poland over the summer, i got a drive locally (25 k) on a bike and brought it back to Canada in my luggage . It worked, and surprisingly it was an ALPS unit that wasn't shot. Rare. The german built replacement also had no screws in it!
I had multiple 1541 drives and all are Alps -- so I've had good luck with them being reliable. I must say a 1541 is a boat of a boat anchor so it's good your luggage didn't go overweight!
@@adriansdigitalbasement I was thinking of discarding the breadbox in Poland and just shipping the drive, but I brought almost nothing with me for vacation so I had lots of room. Even brought back a few PCs ;) Someone actually bought the 220v case off me, so that recouped some of my expenditure.
As for ALPS, the site I went to to get notes had mentioned that the ALPS units are pretty much unreliable. Good work again, I can see you're changing your tone in the vids, I'm thinking of doing the same ;)
Great seeing these deep dives with the scope.
Fixed one of these the other day where the motor wouldn't spin. Turned out to be a bad inverter which seems to be a common issue.
Tants my nemesis! Used a lot in 70’s & 80’s audio equipment, sometimes used for their audio characteristics and low ESR, but used a lot just for their size. I must have changed more Tants "Just in case” than any other componant. Ive obviously canged more eletrolytics but they give away their faults in a more obvious way. Yes a dead tant is in you face but they go from good to bad in micro seconds rather than slowly over time like electrolytic’s. And if a piece of kit you’ve just worked on, goes pop, on a gig or in a studio sesion then say goodbye to your reputation !
Hi, one trick that I use for the oscilloscope is to connect the ground connection from the test point on the lower right corner to the board ground with a jumper cable and remove the little wire that is always in the way!
Those ground wires on scope probes often break. On my Tektronix scope I have had to fix them several times. The wire breaks inside the insulation due to flexing. You can tell if it's broken if you gently pull the two ends apart. If the insulation stretches, it's broken.
8:40 "If you're doing the drinking game..."
Don't drink deoxit ;)
But they say antioxidants are good for you!
It might be opposite of detox. 😔
Good catch Adrian and a very explanatory video, thumbs up!
Impressive investigation and repair. I think you would make a fine forensic detective!
you are a great inspiration, i have reasonable electronic knowledge and just purchased a C64 with disk drive, no PSU and not knowing if any of it works...fingers crossed will be an interesting project
Took me back to my old C64 / 1541 combo. It was a big upgrade from an old Sinclair ZX81 as at the time it was the closest thing I could get that felt like a real computer and not a glorified calculator. Might have to have a rummage in the loft, never know it might still be up there from when I switched to an A1200. Love your detailed explanation of how it all is supposed to work, I got into an electronics repair job but at the time it was all transistors and valves as we were still using 1960s/70's RADAR technology at the time.
Can't believe the 6502 was the problem! Nice work!
great job of logically going through the troubleshooting process...you're a pro!
So did greasing the center hub bring it back up to 300 rpm?
Right, Adrian should've tested that afterwards. Adjusting the speed is easy if it wasn't 300 rpm.
@@YourMotherSucksCocksInHell Yeah its just a little trimpot, it was right there!!
@Mr Guru I think a rusted, unlubricated spindle hub would affect the spindle speed.
@Mr Guru Do *you* know about basic physics? Any non-lubricated, rusty part in contact with the spindle motor is going to affect it.
As a retired EE with 50 years of oscilloscope use I can say that I have had several scope probe ground clips fail. Other test leads as well. Right where the hard rubber for the strain relief ends is common. Grab both the metal ends and you may be able to pull the lead apart and see where the metal failed. It can be very frustrating figuring out what's going on, especially when its not completely broken, just intermittent.
Great video. Although I am not very knowledgeable about electronics, I enjoy watching you fix computers and Commodore 1541. Keep up the excellent videos!
Hi Adrian, lots of fantastic information here! I was hoping you would get into drive alignment as well. Perhaps in a future video?
I guessed the problem with one look at the board (aside from the jumper and the bad socket). Just looking at the CPU you could tell it did not match the rest of the board and had been recently transplanted. Still a great vid on 1541 repair thanks.
When I worked in a school as a lab technician, I have seen this oscilloscope thing happen a few times, Agilent stuff.
I have plenty of experience about test leads and ground leads breaking. Frequent bends does that to even the highly flexible vires. What I have found useful in detecting the location of thew break is to have the meter on beep and then grab different short sections of the cable between fingers and push, sort of trying to shorten the wire. If I am at the break point, it typically makes contact as indicated by a beep.. It is easier to do with rubber or silicone insulated wires, because they are softer.
Often I can also detect an extra flexible spot, where the copper is broken. Maybe a light pull and bend reveals the break in those situations.. Then I just cut, apply silicone sleeving (or heat shrink, peel a short length of the ends, solder the wires and pull the sleeving on.
Considerably more cumbersome when the break is at the very end or even inside the molded strain relief. But that is another story.
I remember taking a hole puncher and cutting a notch in the other side of my 5-1/4" single-sided floppy disks to make them double-sided.
22:31 My station also makes noise when the disk is turned, and it's the platter at the top that makes the noise. This part has worn out quite a bit and even grease doesn't help. I don't know if this plate works on the "clutch" principle, but I noticed that the axle does not always rotate. Programs load correctly.
Ground lead is easy to fix, just cut the plastic away from the copper plated steel spring, and solder a new wire onto it, then cover with some heatshrink sleeving. Use extra flexible cable, and you can make a slightly longer lead, though you will lose some signal integrity on the longer lead, but will make it more convenient to probe multiple places instead of the extra lead you added to the ground lead.
This is one of the best troubleshoot & repair videos I've seen on YT regardless of category. Nicely done. I've subscribed to your channel.
Back in the day I got a new C64 with a 1541, I new zero about computers. I bought a tape drive from a friend and was using that a while til one day he came over and was like, wth are you doing, using a tape drive, you have a disk drive! I had no clue what it was even for. LOL. Those were the days...
I remember in my teens fixing my 1541. It was reporting I/O errors I guess as I had to change the two LMxxxx chips that make up the head amplifier. They were listed as VCR head amplifiers, but I guess one magnetic head is like another. Thanks for the video.
Your videos are gold. I have 2 C64 along 2 drives who both act not normal at all. I'm learning so much on what to probe and what might be the top issues.
The one C64 is my very first computer, I got when I was 8 years old, 29 years ago. It means a lot to me.
The second I bought a year ago, just to be able to find what's wrong with mine, but sadly it has issues as well and this makes it all more complicated. I'm not willing to buy another set. :)
Love your work Adrian. Keep those videos coming!
Just bumped into your channel, this is good stuff.
Fancy meeting you here Phil! Adrian does some great videos for sure.
Welcome! This is a great place to learn how to fix old stuff, or just hang out with other like-minded people and have a nice chat.
@@gregfleury1705 I am in complete agreement with everything you said, but i would like to add that Adrian seems like a genuinely nice guy; e.g. i have never heard him utter a harsh word at anyone, at worst he may cuss at some recalcitrant piece of equipment ;)
Not sure if you're aware while doing it, but your hands are really good actors!
Love your videos! After no success with the pi1541 and the sd2iec troubles with fastloaders i'm extremely tempted by a real 1541
Great stuff, love seeing these 1541 refurbs. My red light of death issue lat year was the CPU being held in Reset. Turned out to be the UA1 IC. Thanks to @GadgetUK164 for pointing me in the right direction.
Nice repair, it might help me diagnose my drive that has similar issues. I think that pcb was swapped out because it didnt match the case mods and the jumper was set for a different drive.
Congratulations on 64k subscribers. :)
5:33
Random needless tip: An old electric toothbrush is amazing for cleaning flux. It's like a point and shoot ultrasonic cleaner. Nice but not an essential for back of the board stuff. It does make tight access areas on a component side much more accessible.
With prototypes small enough to fit in my jewelry-type ultrasonic cleaner filled with 90% iso, the combo can clean anything in under 1 minute :-)
That is a great tip!! Annoying is I had one that had a bad battery so I sent it off to ewaste. But it held enough charge to do cleaning like that. Doh!!
@@adriansdigitalbasement Go to Dollar General, Family Dollar, etc.. and look for a brand called Dr. Fresh, they have electric toothbrushes for $1 - $2.50, I got the idea after my girlfriend bought one to try, and save us some money, and they even come with a AA battery installed, meaning nothing to have to worry about recharging, and while not as great as some other brands for the price they work, and get the job done of both cleaning your teeth, and other things you would use a toothbrush for like electronics. lol!
@@adriansdigitalbasement I've replaced the battery in mine about 6 times now and it's still going strong 15 years later!!! Look for battery replacement videos on YT. It's possible on most brands/models, just requires a bit of desoldering and soldering - well within your skill set :)
Hi again, I also remember that my "toaster" drive (because the way it pops out the disk) the plastic rails for the eject broke, you have to be careful with those, do not pop it hard keep pressure to move slowly the latch, and I had replaced the rails with brass inserts to repair the drive eject mechanism.
Another name I've heard of for those C-clips is "Jesus clips". So called because when they go flying across the room when taking them off, that's how you express your disdain.
28:50: Is that a different drive at the end? I don't see the square cutouts under the LED light on the lower housing that you showed in the beginning of the video. Did you change the lower housing plastic?
BTW you might try some MMO for the drive. Marvel Mystery Oil is good for old crusty stuff like that or Extreme Pressure applications ( I have used it on my air tools for decades now & haven't had a failure yet. ) Also if you put a drop on that old troublesome crusty spot you will find that some of it evaporates away leaving a nice controlled amount of lubrication & protection.
Also, prior to that, 1000 grit black automotive sandpaper is really handy for cleaning and polishing off those parts. Gives you great control on the pool table, also, if you use it on the leather end of your cue prior to chalking.
Enjoying your videos. I like to repair electronic equipment, and would appreciate a video or two with more in depth use and explanation of the oscilloscope for fault finding. My knowledge on their use is pretty shallow but I really want to learn! Any help would be appreciated 👍
Congratulations on the repair. When I restore old gear with tantalums, I replace all of them because they tend to burn a little too often and when one has failed the rest are likely on the threshold. There are I think 12 undocumented opcodes in at least some versions of the 6502B that will stall the CPU so unless you're watching with an analyzer from /RESET going high it's possible to see what you're seeing here and still have a good CPU if the ROM is bad. In the 80s these opcodes were commonly called KIL or HCF (halt, catch fire).
Happens plenty, good little habit you can do is to check the probe calibration.. Should be a pair of clip on points on the CRO which output a square wave 5Vp-p signal, used to get your capacitance adjustment right.. also will make it very obvious when ground wire is dud,,
I think you can safely lift the head counter part all the way up. At least you can on 1541-II. I was anxious about it too, but once I lifted it up, it seemed like something it was designed to allow.
One day we'll get to hear Adrian say "Bringing out my ZIF 1514"
Can't help you with the scope probe. My 40 year old B&K 1465 came with it's original probes and the ground clips still work on that. Probably just the copper inside died.
It's not different than my TS100 soldering iron which recently had the power cable fail in a similar one. Both are soft silicone cables -- so maybe there is a bad manufacturer in China....
Great fix adrian! It was funny seeing 3 hands working at the same time due to the extra cam hehe.
Another fantastic troubleshooting session ... love these!
Just loves your videos, to bad they are consumed so fast hehe more more :D you doing a great job, loving intro in real retro style.. keep up the good work, and real nice way of telling and showing how to handle retro check and repairs.
11:00 Thank goodness that I'm not the only one who's metering equipment just decided to go on the fritz.
Great video and very easy to understand...…………….hi from Tasmania. Australia...…...Cheers
Great work. I suspect that the shorted cap may have damaged the 6502 chip.
Not too surprised about the probe issue. Thin cable constantly pivoting at the point where the strain relief ends is a really common killer of headphone and cheap USB cables.
Murphy got you for a while with that ground lug, eh? Great video as always!
17:05 - Actually in some gear, it would be normal to have in-between values on data or address lines, due to tri-stating.
Another awesome session Adrian. I need you standing behind me at my technician day job. LOL.
Playing board games with friends so could only skim through it without sound, but on the top right of the pcb is a tantalum cap on the 12v rail that exploded on mine. Dunno if you replaced that one but think it might be wise to do so. Old tantalum caps and 12v tails don’t play nice together.
Just FYI , mine was c15 that blew. Your PCB also has it on the top right ....
One of the traps with the original 650x's to keep in mind, though, is that if they execute certain undefined instruction codes they go off to Neverland until a reset, so they may seem unresponsive when it is really a case of GIGO.
Indeed.... I read that in the "C" versions they changed it so it would just run a "NOP" when you issued any illegal instruction to prevent that locking up.
The two camera angles work well, and if one start crashing you have backup! :)
Amazing video. Excellent production. Very knowledgeable. I love it!!!
Nice work! The ROMs are always the first thing I check (after voltages ofc), especially on longboards. One of the ROM chips are very close to the rectifiers and that is often bad. One of the few bad 6502's I found was actually also in a drive (SX64 internal).
Definitely had the scope ground leads fail before. On some scopes, you can provide the ground using a banana plug on the scope. It isn’t as accurate as the per channel grounds but it is probably good enough for what you are doing here and makes scoping different parts of the board even easier
6502 could have been zapped caused by someone not using a static strap. Glad you found the problem. Interesting now most of the chips have yellow dots. When you first started I thought to myself something is not like the others. 6502 was black and clean so after replacing the cap, I would have swapped out the 6502 as it seemed like a likely suspect. If not working still then on to the oscilloscope. What settings are you using for the Oscope? Thanks again for showing this and Great work!
Small correction and I’m sure you probably know but the reset vector on the 6502 is at 0xfffc not 0xffff. Great video.
Great job Adrian.
I've had my share of trouble fixing that typical ALPS scratching noise from the spindle setup and got a result more or less like you got with silicone grease. I 'm very certain that in my earliest memories from the 80s those ALPS drives were actually pretty quiet back then. Looking at other drives like the Mitsumi one , I think that spindle shaft should barely move at all. The plastic part locking on to the disc should pretty much move freely and not turn the shaft that holds it in place. I believe silicone grease is too sticky and causes the spindle shaft to turn and scratch.
Wonder when Adrian took apart, cleaned and re-greased the clip mechanism if the RPMs went up on the drive?
Your Deoxit drinking game reminds me, it's been forever since I've seen Neil at Retro Man Cave use his baking powder for fluffy muffins to clean a case. I've had success with both baking powder and Deoxit too, even if I can't find the same type here in the States.
Thanks for another great video, I always enjoy watching them! Regarding the dead CPU, I do not know much about them but if a ROM/RAM was bad, would the CPU still show activity - while trying to access the ROM - or would it just try once and then give up?
Yes we sure do love your repair video's😁👍 Thanks!