Macintosh Classic, Classic II & Color Classic repair +External SCSI drive restoration Apple HD20SC
HTML-код
- Опубликовано: 29 мар 2024
- PCB Prototype the Easy Way. Full feature custom PCB prototype service. www.pcbway.com/
#marchintosh
-
Support me on patreon.com/Epictronics
Join me on Twitter: / epictronics1
-
Tools I regularly use
DeoxIT D5 Contact Cleaner
Hanstar 861DW Rework Station
Pro'sKit SS-331 Desoldering Station
UNI-T UT61E Auto Ranging Multimeter
UNI-T UT890D Manual Ranging Multimeter
MESR-100 mk2 ESR meeter
PINECIL Soldering Iron
PinePowerPSU
TS-100 Soldering Iron
AMTECH NC-559-ASM Flux
Kester 951 Flux pen
MaAnt Grinding Pen
Multicore 60/40. 0.38mm and 0.5mm solder
TL866 II Plus Programmer
RIGOL DHO800 70MHz four-channel digital scope
Tektronix 2246A 100 MHz four-channel analog scope
InfiRay P2 Pro Thermal Camera
PCBs from PCBWay.com :)
--------------------------------------------------------------------------------------
patreon.com/Epictronics
Join me on Twitter: / epictronics1
Music by Karl Casey @ White Bat Audio 
Наука
The still photo of the soldering iron 😂
:)
Whew! You crammed a lot into this video. I'm tired just from watching it!
yah, it was a bit much this week lol
These old drives are SO important to the history of home computing. It is a shame kids today will grow up without the experience of dealing with these mechanical drives, the joy of the sounds they made, the frustration when they crashed.. both good and bad, as with everything in life!
Totally agree. Love the sound they make :)
I was born at the end of the 90s so unfortunately my experience of mechanical drives is quite boring.
@@SonicBoone56 there are still plenty of old machines out there, relics to time, in old insurance company basements and municipal building storages.. they need to wipe the drives and sell those things. I know because in the small town where I grew up they STILL have old IBM PC systems in the basement.. Yup.
Interesting technique for holding a hot soldering iron at 12:08!
;)
I was thinking the same!
Let's hope it wasn't turned on for the photo lmao
Edit: early comment, I see now you did this on the 3rd drive.
Often these drives with stepper motors have stuck bearings in the steppers, the grease turns to glue after a while. The one that spins might just need a drop of bearing oil on the stepper bearings.
An ultrasonic cleaner would make you jump for joy. In a couple of minutes it will clean out the grime and grease residue, leaving the part squeaky clean.
It's definitely on the wish list : )
Yeah Rodime drives were a thing back then. A friend and I bought two SCSI 105MB Rodime used drives (from the same local guy) for our Amiga 2000 machines. His drive lasted about 3 months then died. Mine was still working at that time so soon afterwards I sold it to a local guy as a working drive for some good money. I assume it died eventually but that wasn't my problem hehe!
I thought they only made those proprietary drives for the Mac 512Ke. learning something every day
You may be able to fix the Conner drive by taking it apart and removing the rubber bushings (they degrade with time and become sticky and then turn to goo) that cushion the voice coil assembly from the screws that go into the magnets. Also the gasket for the entire drive tends to turn to an oily subsistence as well. Make sure you ware gloves when taking apart this drive as the gooey rubber tends to get everywhere.
I'll give it a try, thanks
Use "Low Melt" solder to make it easier to remove components. The low melt solder lowers the total melting point of the older solder, makes it much easier to remove components.
Yes, I use Chip Quick whenever it's not suitable to use the rework station.
ah, the leg de-bending technique you use is not something i have thought of doing. that's such a good idea to reheat the solder to unbend the leg properly.
Agreed. I gotta start doing that.
Honestly no reason to replace that huge capacitor. Caps that size tend to almost never fail. And most people only want old mechanical drives for authenticity or nostalgia. Still worth saving them.
For the Color Classic, you may try looking for broken solder joints around the flyback and the neckboard. If the grid pins are grounded or left floating intermittently, that would cause all sorts of weird behavior. Broken/corroded pots might be a problem too
I don't remember if I have reflowed the solder joints on this CC. I'll check. Pots are cleaned but sins this looks very much like bad pots, I'll clean them again and more thoroughly this time
@@Epictronics1 Just don't bang the CRT neck. At some arcade/home console museum there was a small Sony Trinitron where the picture would intermittently become super dim and fuzzy. After some resoldering and cap changing with no results (it would work great for hours, then go dim and fuzzy, sometimes so dim you have trouble seeing it's turned on at all). When I had it open, I whacked the neck of the CRT, thinking it might clear up a temporary short. Instead, it made a temporary short permanent, wrecking the CRT. At least it revealed there was a temporary short inside the CRT.
@@senilyDeluxe Let's just hope it's something else :/
I'm thinking it could be a problem with the G2 (screen) voltage. On many displays an adjustment for this is built into the flyback/rectifier module so hopefully that's not bad.
sometimes on older drives, the main motor gets a bit stuck and is unable to spin up on its own. try applying power and immediately manually spin up the platter. this fixed an old prodrive 80s of mine.
I'll give that a try
Goodbye Marchintosh...Hello Appleril!
The Apple II is coming out of storage :)
The Color's issues might not be caused by something else, but by several things, including the scorching diodes and bad caps.
One thing, I would check next is other diodes, maybe look at transistors... check for other excessively hot components, if you have a FLIR. Maybe replace thermo pads and grease underneath heat-sinks.
And overall, check whether there are loose legs or broken solder joints.
And maybe check the values of the poties, before switching on and after the fault appears.
Great suggestions, thanks
I remember back in the day the C64 was completely silent except for the disk access. I believed that some day completely silent computers would be a thing. In spite of having 8 fans and a water pump, my computer is completely silent. So I was never fond of disks. And I was never fond of CRTs either. They were a bit flickery and I always thought they were a tad blurry. So I love the machines, but not the old media.
It's the same thing with classic cars. They look great, but they're sh*t to drive and have lots of safety issues.
The phrase "they don't build them like they used to" is most of the time used incorrectly. They don't build like they used to, because progress made cars better (not necessarily prettier, though).
Your CRT was blurry because like most people they bought the cheapest thing available. If you look at a high end Sony CRT it looks amazing.
@@bikkiikun not true for cars, but it might be for other things. I think old school fridges were better than modern ones.
@@g4z-kb7ct I've seen high end sony and NEC displays. They are significantly better, but still blurry.
@@g4z-kb7ct and they still hurt my eyes cause of the flickering.
We had a Classic II when I was growing up. It had a duck hunt clone, not sure if it came preinstalled or not, but when I’d enter my name for the high score “John Doe” was always on top. One day my parents were watching the news and the police were looking for some murder suspect in LA, and he was a “John Doe,” not knowing what that meant at the time I flipped shit thinking a murderer was in our house using my mac.
🤣
Thank you for straightening those capacitor legs ;) So many times I didn't and regretted it hehehe
Over-brightness could be a bad trimpot as they often get wear spots on them where there's no contact, meaning the value of the resistance is zero. Can also be caused by the flyback adjustment pots wandering over time (although they shouldn't wander). Or something in the brightness circuit on the board has failed.
I have cleaned the pots but I'll clean them again
Yay, Würth caps! My favorite. I like them because they tend to be the lowest cost amongst the higher performance capacitors (low ESR, temp, etc.) Way cheaper than similarly rated capacitors from Rubycon, Nichicon, and Chemicon.
A local friend always uses Wurth caps but only because they are red heh!
@@g4z-kb7ct They certainly stand out. :) Only downside is that they don't sell axial capacitors. But they're still some of the best priced polymer caps.
33:58 - There was a rare SCSI conversion upgrade option for the Hard Disk 20. Very few people got it, though.
There is a solder bridge on the + leg of C9 on the mac classic
I was wondering if anyone would notice :) I did, and I fixed it
Good call, I saw it and came down here! Nice!!
Another excellent video and work! Thanks for sharing
Thanks Rudy!
This episode took a bit of "elbow" & literal grease!
With enough hours and PTFE there isn't much one can't fix :)
Be careful when manually turning the platters. You shouldn't rotate the platters backwards, because you can crash the heads and destroy the drive. If the heads have any tiny bit of resistance at all, you can rip them clean off turning the spindle by hand.
As for the ST-225N that doesn't spin, did you check for delayed start? Most SCSI drives have an option for delayed start, which keeps the spindle stopped until told to start by the SCSI host controller.
I'll check, thanks!
21:55 that icon on the left, looking a little sus.
Fwiw, the classics have system 6.0.3 in ROM. Use cmd R when powering on.
I keep forgetting. Thanks for the reminder
I just use high quality low ESR caps in general for anything I care about.
oh no, I was hopeful for the Trinitron! What about moving the drive trimmer back and forth a bit? Maybe it needs to be "cleaned". And you have a working miniscribe! Mine works but it's unusable...
I'll work on some Macs soon, I'll keep this video in mind!
I still haven't given up on the Miniscribe in the Canon lol. One day we'll get it running :D It sure looks like it could be corrosion in a pot. I have cleaned them once but I will clean them again.
@@Epictronics1 isn't the drive pot in the flyback? Maybe just turning it back and forth several times will do the trick - not when it's running :)
@@tony359 yes, the gain is very likely on the flyback. I'll check!
Drifting brightness/G2 voltage is a common symptom of a failing flyback. I suspect you have a failing/faulty flyback on that color classic.
I'll check, thanks
I suspect that the glitches in the color mac are due to bad components on the neck board. Possibly a bad solder joint or MOSFET.
I would have thought that turning the hard drive motor against the normal direction would damage the drive heads. I'm just assuming they're always connected. Am I missing something? BTW, the Chemicon SM caps are not particularly exotic. They have many that are exceptionally good, starting with the fairly common KM series, if memory serves.
The Classic II needs to be adjusted, so the picture fills the screen. All that black makes my brain itchy.
yep, we'll fix it proper in the upgrade video
Weren't they designed to have the screen resolution set to a specific DPI?
The fault on the Color Classic could be a faulty or dirty pot.
I think I'm gonna clean them again
i have a 250MB quantum harddisk and a working sony floppy drive but no computer for them
50 caps, including several large ones, to be replaced in the Color Classic's analog board... Apart from time consuming, that doesn't sound exactly cheap. How much is it for all of those?
I ordered these together with caps for other computers so I don't know unfortunately
did you check scsi termination!
Yes. Unfortunately, termination and drive ID were checked
"Unfortunately it still works" 🤣🤣🤣
:)
It's true though. Nothing worse than something that magically fixes itself.