Don't use a blowtorch to fix your C64!
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- Опубликовано: 6 сен 2024
- #troubleshooting #repair #tracerepair #c64 #8bitdanceparty
Let's dive back into another C64 repair! This time, a machine that has been "burned" when someone attempted a previous repair. Let's see if I can fix it!
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Adrian's Digital Basement ][ (Second Channel)
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-- Tools
Deoxit D5:
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O-Ring Pick Set: (I use these to lift chips off boards)
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Elenco Electronics LP-560 Logic Probe:
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Hakko FR301 Desoldering Iron:
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Rigol DS1054Z Four Channel Oscilloscope:
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TL866II Plus Chip Tester and EPROM programmer: (The MiniPro)
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TS100 Soldering Iron:
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EEVBlog 121GW Multimeter:
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Magnetic Screw Holder:
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Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
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RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
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--- Links
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--- Instructional videos
My video on damage-free chip removal:
• How to remove chips wi...
--- Music
Intro music and other tracks by:
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@itsnathandivino
"Who would rip off bypass caps". 20 minutes later "I couldn't find any so I took them from the other board" 🤣
Yeah, it's almost as if whoever had this before treated it like the donor board it is.
@@stevethepocket well, save from using a 100 watt soldering iron for some removals and thermite for others.
Today, Adrian Like a lumberjack !
Yeah, saw that as well. Let's see what happens when Adrian will try to repair the other board he took the caps from ;-)
12:41 I'd recommend making a small slit in the wire coating with an X-Acto knife before heating it up, That way you know where the coating is going to separate. Also I usually only do that if the wiring is serial - ie, I'm connecting the same wire to multiple spots and I don't want to cut and splice it.
First thing I thought of seeing that socket was my father's ancient soldering gun with the trigger light. Those things put out 100w+ at a go. Great for thick cable wiring, not for boards. When I was a kid about 10 or 11, I tried using that gun on a circuit board to add a wire on for and that burn type happened. I laughed so hard seeing this here.
I thought exactly the same, as a kid I used to like making the tip glow red by holding the button in way too long, a weller if my memory serves me right. 🤣😂🤣
Was what I thought too. I still have (somewhere) a soldering gun, I bought that when I was 15 or so. I only use it for cable wiring. But today I have that soldering device that Adrian showed. Whoow, USB and very good!
@@JaapGinder I ended up with a Hakko instead because it's prewired to be ESD safe. That's the one thing I worry about with working on old computers, and the USB soldering irons are a pain to ground properly to be ESD safe.
Good old soldering gun, I member the tip with the shape of a F1 trace 😅 (a circuit is a circuit...)
I've used my 100/140w soldering gun to do lots of work, even basic SMD work and it never caused board damage. I then used it to (try to) repair the through-hole power supply in a VCR and it damaged the board. Board lamination quality is probably a huge player here.
Adrian, you have the patience of a saint and amazing tenacity. I love the content. Keep up the good work.
My own guess, they use the cheap 130W (maybe more) L-shape soldering iron (for pipe) to solder, that's very hot and a thick tip ruins the PCB and socket, I've been using that when I'm 11 years old, soldering without a table, always have ball of solder rolling off and burn my leg, nostalgia.
:horrifiedface:
That was my first thought as well: the good old (large) Weller soldering gun.
My first ever repair attempt was using a propane torch which I tried to use as a substitute for hot air station. Oh the good ol' days.
Wow, don't ever do that
How much was left of the thing you tried to repair? How charred did it get? XD
@@CraftMine1000 I remember I tried to space it out so it won't melt everything, but the chip I tried to desolder still died)
Propane burns at what? 2000 degrees. I never have heard of this. I never did this one.EDIT 3,560˚ Fahrenheit/1,995 degrees Celsius.
i've done it SOMEWHAT succesfully, however i was just salavaging parts from some e-waste PCBs because i didnt want to wait for months for shipping from china, parts survived board not so much
I've been in the industry for over 30 years and I was a component level service engineer on the BBC micros and Archimedes. I have NEVER seen a bodge job that bad :-)
Hopefully none of mine ever look that bad
@Cowasaki Electronics Well you need to move around more often and experience life out there in the big wide world hehe! That type of damage is common nowadays. Checkout the arcade scene for some butchers beyond belief. I once had an unbelievable repair, someone pulled out a LM7805 and replaced it with a LM7905 LOL! Yeah they look the same so they much be the same thing right? LOL!
@@johnbos4637 Difference is that I now generally build, repair and modify valve amplifiers plus I can choose what to repair and what to refuse.
I have to wonder if any previous owners of all these damaged C64s ever end up identifying their shoddy work in these videos should they see them, that would be embarrassing, haha! Great video, Adrian!
This is why I mostly use dual wipe sockets instead of machined sockets. The dualwipes makes much better contact with desoldered chips that has short legs.
I like dual-wipe, but I think they can suffer capillary moisture retention that oxidises pins. I think the machined ones are interference press fit that are too tight to let oxygen between them. Basically it's easier to make contact with DW, but if a machined one makes contact it's permanent.
Bil Herd said in a (now) old 8-bit guy video that you should always use dual wipe. This burned in my brain. For some reason I don't trust those hole-type (machined?) sockets.
What happened with the original socket was probably way too much solder was used, and it got sucked up into the top side of the pins. Maybe too much heat warped the plastic a bit too.
I prefer to use round pin sockets only with round header pins, but round pin headers are great for making daughterboards for wipe-pin sockets, such as a 2513 to EPROM adapter board.
Those machined precision sockets are great for new chips but are really bad for desoldered parts. They can even get damaged when there's an excess of solder left on the pins. That's why I almost always use dual-wipe sockets when in doubt. They are way more reliable than the cheap single-wipe ones Commodore used and are also mechanically tolerable to desoldered and/or otherwise abused parts. Add to that the bonus of being way cheaper than machined sockets... Dual-wipe sockets have never let me down. The only way to ruin them is by ramming too thick of a conductor in them, like some ROM adapters, Kernal switchers and so on, they might get bent and not work with the flat pins of regular chips any more.
I almost always use dual wipe sockets because they contact the pins better. Look at a machine pin socket that has had a dip chip in it and you'll see a groove worn in the hole. Once the chip has been removed and replaced a few times the machine pin socket becomes sloppy whereas dual wipe sockets will hold dip chips well as long as they are not abused by inserting an adapter like you said. For desoldered chips I always use wick to remove the bulk of the solder then just sand the legs with 400 grit sandpaper then the legs are smooth and the chip slides in easily and can be removed without pulling pins out of the socket.
Fun fact, later C64 PCBs were made from compressed paper fiber with a coating instead of G10 in order to cut costs even further. Though at least Darth Jack did it to actually lower the MSRP rather than just keeping prices the same and pocketing the difference. He might have been an assh*** but he did believe in selling affordable computers.
Seeing circuit board damage brings back fond(?) memories of repairing CB radios back in the 1970s. People would do so many things wrong; not quite to the point of a propane torch, but plenty of cases of acid (plumbing) flux, 100+ watt soldering guns, you name it. Combine that with poor quality PC boards and I saw a fair number of burned and delaminated PCBs, broken traces and feed-thrust.
Kudos to you Adrian for sticking with it and finding the problems.
This is a good candidate for a one of those C64 modern PCB replacement projects!
I'm loving all the retro computers and consoles that are getting much needed modern PCBs that remove redundant parts like tons of resistors and capacitors, plus using modern PCB techniques which means no lifting traces easily and whatnot. Very exciting times
Wow. Nothing quite like injecting other problems during troubleshooting. Persistence and a lot of self-checking won the day. Well done!
The best way to solve problems is replacing them.
A couple of years ago I came across your channel and watched you working on a c64. I didn't understand anything you were doing but watched right till the end,I promised myself never to do it again.You've bloody done it again!.You should have your own TV show,I'd watch
That was a funny repair. Whoever butchered this C64 previously wanted to be sure, that the person which would repair that, would have a lot of headaches. I'm absolutely with you about the point, that trying to repair a board which s.o. already tried to "repair" is usually by far more complicated. Great job Adrian!
These C64s can survive a barn, and now we have confirmation they can survive a butcher shop.
That was more like jack the ripper hehe!
I'm not great, but everytime I messed up my C64 repair I fixed it. I have a bodge wire where I removed a trace. Then again I have a 2nd one where I lifted a trace, but it was still attached, so I didn't bodge that. IT's on the cartridge slot. I had to replace it. De-oxit helped..........until it didn't. It got to the point where de-oxit was lasting less and less until it did nothing. New slot = fixed.
I blame this on all the electronics stores (back in the day) selling you basically plumbing soldering irons that have no temperature regulation and plug right into the way. So hard to get things right using those. Even the "learn to solder" kits at Radio Shack came with those. It's like they wanted you to fail.
when I was a kid and I was trying to solder without anybody telling me how to do, I didn't know flux was important - and didn't know flux was in the solder itself. So I would melt some solder on the iron's tip and then (when the flux had all burned away!) apply it on the joint/component. Since the solder would not flow, I thought it was a temperature issue so I would get the biggest and most powerful irons I could find.
The results were more or less what you saw on that poor board - well, maybe without the brown patches! :D
Great video as usual!
That's why you should use liquid flux. Then you can place it on the lead area and be more precise with it. Particularly with thru-hole parts as the flux will fully penetrate in the barrel and not burn off right away.
Messy, but you can push a conventional wipe-pin socket into the turned pin socket and then fit the original 'short-pin' IC.
OMG! Someone really took out the flamethrower on this poor thing!
Cool fixes Adrian!
I had a similar thing happen to me when I fixed my toast rack ZX Spectrum, where I suddenly lost all of its upper memory because I accidentally hit a trace while lifting out a GAL chip. The damage was also totally invisible and the traces on the Speccy are really, really fragile and exposed as mine lacks a solder mask..
I was about to replace all of its upper memory chips when I discover the broken trace. Good thing I did a full continuity test first; face palm :-)
or a heatgun (i've burned boards similarly stripping parts from them)
It's amazing that board didn't need more work than it did!
Adrian, for the chips with narrow, short or damaged pins, I have put one into a machined-contact socket and soldered it into place. The chip & socket header assembly can then be used in another machined-contact socket on the board. I learned to do that at work years ago, when needing to swap test EPROMs frequently. I used Augat brand sockets, not sure if they're still around or not. Only once or twice did I have an issue, that was where the little cylindrical contact inside a socket pin was missing.
Dual wipe sockets give a better connection when using pulled chips.
Yep a repair with a machined pin socket isn't a repair at all, it's just a slightly delayed failure
You can clean up desoldered pins a bit by (quickly) using a desoldering gun on the pin (I mean the type that has a combined heating element and desoldering pump) then applying some flux and reheating the pin to smooth out the remaining solder, then clean off the flux. You end up with a clean lightly tinned pin basically a tin plated component leg.
One thing I tend to do with plated holes when cleaning up after a poorly done prior repair is to use a pushpin as a mandrel to push any potentially loose barrel plating back into place, and the pads on that ROM socket would be a prime candidate for such a step. Another step is to use a small dowel to press down the edges of pads that may be beginning to lift. Neither step will restore the lost bond between the copper and fiberglass, but will go a long way to improving the post repair appearance.
What about via repair kits?
@@SonicBoone56 I work in a production environment, and such ‘repairs’ do not comply with IPC standards for long term reliability, so I have not used those in ages. I have found that in a pinch, a bit of wire soldered into an open via will work as well if it’s just passing a trace from one side to the other. All bets are off if the board is multi layer.
@@Renville80 so you're basically screwed if it's multilayer?
@@SonicBoone56 pretty much, unless you don’t mind adding jumper wires to replace the broken bonds in the damaged vias.
The most satisfying musical interlude of all the repairs
It feels SO good when you stop beating your head against a wall. Good job!
Knoledge, experience... But a lot of patience too. Great job Adrian: I enjoed this video so much. 👍🏻
Una riparazione eccezionale. Ti seguo da tanto e come te condivido la passione per la tecnologia e l'informatica vintage come potrai vedere dal mio canale. Nonostante non abbia mai capito l'inglese, grazie alla tua pronuncia fluida e chiara riesco a seguirti nei tuoi video e a capire quasi tutto. Sei veramente bravissimo. TOP !!!!
Beautiful fix Adrian! I really want a C64 someday and I'm learning all I can as far as troubleshooting goes. Its good to know that even a rough board can be fixed. Thank you for your time.
If it's a single layer board, it can almost always be repaired as long as you don't have big craters where the actual connections lie. It's all down to whether it is worth fixing at that point or not.
I've burned a few boards like that trying to use hot air to desolder DIP packages. Didn't mangle so many traces in the process though.
Don't use hot air on a C64 PCB the later ones were made from a coated compressed paper fiber instead of G10 and have relatively low tolerance for high temps.
Quick tip while we're talking about not torching our boards... auto-ignition temperature of isopropyl alcohol is 399C. There's no need for soldering irons to be that hot, but just in case anyone has theirs set that high, make sure you let the isopropyl fully evaporate first.
Good tip!
I think I have set the desoldering station that high when I was trying to get a modulator off the board.
you'll see warping and burned spot from using a heat gun either to hot (most likely) or holding the heat in one spot for way to long. i worked in a local authorized commodore repair shop. for a couple years and you would not believe the stuff I saw in the 80's that customers brought in from trying to fix it themselves.
loved working on commodore equipment!
Your diagnostic skills never cease to amaze me.
Good insight here that diagnostics tools only really show where the error was noticed, not where it originated.
If I had a nickel for every time it was a teeny tiny problem that I only saw after everything else! Glad you ressurected that awesome board!
I have problems with machine pin sockets. So much so, that I can't trust them and have switched back to dual wipe sockets. Just as you observed, they will sometimes fail to make contact with all the legs on pulled chips. In addition, when removing and reinserting chips during troubleshooting, contact will become intermittent, requiring you to push down on the chip. I have also observed that chips are more likely to pop out of machine pin sockets. I don't have these problems with quality dual wipe sockets. BTW - seeing all the burning made me laugh...poor board. Looks like a smidge too much wattage on the iron used for that "repair". I also love the heavy duty bodge wire. Reminds me of old times.
I damaged a MK2 board with a BackSID because I put it in backwards. I now fill the half-circle of chips with white-out and I hope I keep from doing it again.
That's the mainboard that's in my C64. I have one of the last ones made when my original died back in 1986, I got a new one, and it was a white C64C keyboard in an older C64 case, they were obviously trying to use up some old parts. Getting ready to shoot my own video on retrobrighting and restoring it as the keys are yellowed now.
That area over by the RAM actually looks like it has delaminated, and for me, that has always been the point where it’s time to salvage the good parts and toss the rest of the board. The layers of the board are separating, and will eventually strain the plated barrels and cause more problems later.
Once the inner layers start to mess up, you're kinda screwed
@@SonicBoone56 suitably appropriate name you have there bud lol! C64s don't have inner layers. C64's are very easy to fix, even ones in worse condition than this one in the vid.
@@johnbos4637 that may be the case, but in this case, between the existing pad and trace damage, the heat damage to the surface, and the inner substrate separating into layers, the long term reliability is just not there. Even though Adrian’s field found 64 has trace corrosion, the board itself did not show any separation of layers, so that one will be fine as long as the traces hold up.
@@Renville80 There's nothing inside the layers so even if they are split it won't affect anything. Any separated vias can simple be fixed by poking a wire through the hole and soldering it both sides. If a trace is broken simply patch it with a wire. Even if every trace was burned off the board, as long as you knew where they were it could be rebuilt. The old C64's are very easy to repair. It's definitely not rocket science.
That board sure looked like they used a propane torch on it. Glad you were able to see through all the chard mess and finally come up with a solution.
That machine is now a grizzled, battle-scarred badass.
"this motherboard is a real basket case" ... *waits for literal PCB basket*...
Funny you mention a torch. Was at a hamfest and a guy was selling 1 lb grab bags of parts from boards. Talking to him for awhile and found out his technique to remove parts was to heat the board with a torch and rake over top with a wire brush till the parts fell out. I didn't buy anything lol
Holy damn, I wouldn't buy anything either.
It's singular that Adrian likes round machined pins socket and consider the other trash while Sean from the channel "Classic Arcade Repair" has the exact opposite opinion.
I find turned pin sockets reliable over time, as long as they work initially with short pin ICs...the dual/single contact sockets work when brand new...but over time they suffer metal fatigue and fail...it may take many years, but eventually they do fail and I don't want to diagnose again boards I repaired previously
We used turned pin sockets in crash test systems, nothing else survived.
Video title: "Please don't try to fix your C64 with a propane torch!"
Hank Hill: "GOT-DANG IT!!!"
This is the kind of board you use as a donor for a repro board. I admire you saving it but it's probably going to eventually break considering how marginal some of those traces and vias are.
Ya, seems to better off just as a parts board when the pcb is that bad. those traces was clearly pushed sidewards. Someone has done some crazy things to it.
yeah. Would be perfect as a donor for a sixtyclone board
Perhaps, but chances are it won't break, it'll be fine for decades I'm sure. Nobody will flex it.
@@mrdali67 You don't throw a car away when it's been hacked by a bad mechanic, why do that to a C64 that aren't being made anymore?
@@CirnoBush the c64C PLA is different than conventional c64 PLA. That being said i have repaired many boards much worse than that one in 30 years i have been doing it and they are still working.
Yep. We were screaming at the screen when you flipped that ROM. You had taken out your reminder notch to get at that broken trace. ;P
It was lovely to learn about this Board as I have two of these 252311 boards and A and B revisions. Love my C64c
the board in the vid is the worst one to own because Commodore integrated the color ram into the pla so if the color ram goes bad you're out of luck. every version board before this is better.
13:09 Who would steal bypass caps? lol
The "haha moment". Unforgettable. I really thought this was a lost cause. Thank you Adrian. Great work!
Nice work Adrian! Kids - Don't try to repair old electronics using hot air either. Unless you want your PCB split in funny way :D
Unless it's a proper hot air soldering gun
@@SonicBoone56 nope. Old pcbs weren't designed to handle hot air. At first you will notice color change, then the surface will swell and traces will start to detach. All in all it's recipe for disaster. Even the way Adrian is using it is dangerous.
Hey Adrian. In order to clean that kind of mess you may try to heat board to about 100F and then try to use IPA on some ear stick. If it fail repat procedure with some flux added before heating. To make pads nice and clean it's always worth using wick desoldering tape and some amtech flux (eg. 223 or 559).
I love your channel! Thanks!
Yeah I cringed a bit at the use of acetone. It's much better to use a bit of elbow grease and some IPA or use a dull tiny flathead screwdriver to scrape off the gunked on flux. Much safer anyways
I actually have butane powered soldering iron that is over 40 years old. It's called "PORTASOL" and made in Ireland. The butane burns in a little chamber behind the ion tip.
there are some super powerful flux dissolver stuff! You can tell from the first spray that it's LOADED with rare and expensive solvents you don't usually use. Works really great but expensive
How funny and relaxing you make all of this repairs. Thanks a lot.
Thank you for saving this short board! (my favorite revision)
I just love watching your videos. This is something I could never do or understand. Thanks again.
It looks like someone much later on removed the caps and RAM than did the original "work". Someone must have given up on it and just used it for parts. Glad to see it come back to life again.
I was about to try to fix my C64 with a propane torch... Glad I saw this video
"It freaking works!!!" - love hearing those words. Hehehe...
I laughed at "The Ben Heck style of wire stripping / soldering."
The DAD DANCE gets me every time lol
i like the use of the denture brush
BTW Adrian, you were experiencing the exact same problem I had last weekend when working on a C64. I desoldered the MPU and installed a machined-type socket, and kept having intermittent problems which turned out to be the MPU pins not staying in the holes since they were trimmed short at the factory. I took that socket out and put in a double-wipe socket and that did the trick for making good contact. (That C64 was not one of the blowtorch-burnt ones.)
Subbed and liked 99% due to your dance party dance. Also, all the info you share that's helped me resurrect several systems, but it's the dance that got me.
Maybe try to tin the short legs to make it better contact with the machine socket.
or better, put the chip into another dual wipe socket, solder all the legs into the socket and insert that into the socket on the main board (a dual wipe, not the incorrect machine pin type he used). It's not difficult if you know how.....
Man these repair videos are the best! I wish I had more time to get to my work bench and tinker.
Looong time ago I replaced a VGA port on a mobo with a torch and Works for 5 years until my cousin sell it. Good old disaster days!
I was thinking of a 60W plumbers iron and a stick of plumbers solder, lol. At least they didn’t use plumbers flux, there would be a lot of missing traces if they had.
Good job. Hoped to see some of that green protective paint applied at the end, but that's me!.
19:48 - I must've missed when you upgraded the tester display but man, it looks so snazzy with that OLED.
Flux-Off spray takes care of that really bad flux, it's pretty strong stuff and often takes of printing on some stuff too so use sparingly.
A good friend of mine who has really great electronics knowledge (builds his own 8 bit computers and synths and such) used to desolder large components using the kitchen stove.
Only did it to boards that were junked, and definitely caused damage worse than this c64c board has, but it reminds me of that kind of damage. Honestly wouldn't be surprised if a stove was used!
My friend has a proper desolding station now!!
8:21 just underneath the via to the left of the plier tips you can actually see the torn trace (little bright bit of copper to the top of the bend in that track)!
German has two words you might like: Verschlimbessern and Kaputtreparieren. First one is when you try to make something better, but end up making it worse, and the second is when you try to fix something but end up breaking :)
Really enjoyed this video! I get to see diagnostics and repair techniques that I need to learn how to do, like using probes and oscilloscopes and correct sized bodge wires. Also want to know to how to use those replacement through hole via kits. Still have lots to learn! Congrats on getting this to work. Repairing a failed repair from somebody else is ALWAYS the worst.
Ben heck’s style of soldering is my absolute favorite.
Yeah, it's always fun to chase your own tail that way, done it more than a few times over the years.
I refer that to being a defective keyboard-chair interface on the test bench.
I have an SDK85 that I fixed years ago after buying it from someone who tried to de-solder some IC's with a torch. Good comedy...
Good diagnostic job on this one.
Good job! Leave no stone un-turned
My problem with the "cut the bad chip out" philosophy is that sometimes you end up THINKING something is bad, only to replace it and find out that the culprit is elsewhere. In the case of bad sockets though, go ahead. It's really hard to get them out intact, and often not worth the effort.
For desoldering THP boards, I like to wet the pads in question with fresh solder. Heat up the pad and pin with the desoldering gun until you can jiggle the pin, THEN suck while jiggling the pin. This allows you to suck out all the solder out of the plated hole, and prevent the pin from sticking afterwards. Only do this when you know the board is THP though, because holding it on too long for non-THP boards will end up just lifting the pads.
22:25 Surprise look!😄 Awesome repair!!!
Commodore use throughole components only.
First to all you need to buy a Hakko desoldering gun, with this tool remove any IC is very easy.
If you can't affort a Hakko desoldering you can find the Yihua 948, this is a very good option if you are in budget.
Best Regards
"Traces, traces, we don't need no stinkin traces!"
You can solder an IC socket with turned pins on the ROM chip and you'll be able to use it again.
You can scorch boards like that if you go ham with a hot air station, or worse electric paint stripper gun that some people use instead of a soldering hot air station! If you want to re-use the old ROM you could solder it into another turned pin socket, the pins fit perfectly into a turned pin socket. I've done this in the past to rare chips that have badly corroded pins that couldn't be fixed any other way.
Here in the Netherlands nail paint remover is usually acetone free....
You can buy acetone at the drug store, in small glass botlles for about 3 euro for 50 ml...
I use a small torch sometimes to remove stuff from boards, but only if the board is junk...
What are they using in nail polish remover instead of Acetone?
Methyl ethyl ketone perhaps?
In the USA, Acetone-free nail polish remover is available here too, and I believe that they use Methyl ethyl ketone.
Ok, so look at the channel called Trevor’s Work Bench. In a Video form April 2020. He uses a butane torch on a C64 board to remove chips. I was shocked seeing that.
Love Adrian’s enthusiasm. I wish I knew what he was talking about 1/2 the time 😂
If i don't care about the board but want some chips off it, i heat it from beneath with a heat gun an bang the board hot on the table. The solder flies down and the chips jump out. And with the chips all the components around them. If the heat gun is adjusted to high the damage to the PCB is similar. So my guess is that someone wanted the RAM but didn't care about the board, probably because of the horrible job de/re soldering the ROM.
Title - "Please don't try to fix your C64 with a propane torch!"
Me, pre-video - "Why did you need a propane torch Adrian?"
*watches video*
Me, afterwards - "Oh! Nevermind, it *freakin'* works!"
Hitting the like button and watching it roll over to 1k was just about as satisfying as the video itself.
Love the emotions--- you make it look so easy!
I'm an Atari guy but I love these videos. I learn so much about repair from your very informative videos
34:48 when you were looking under the microscope.. thought to myself ! Jeez some of the trace looks wonkey … I hope Adrian test it 😂 and that was actually the problem …
I would use that fiber pen and remove the top layer of oxides and carbon on the burned spot. The burn could cause leakage paths in the circuit.
More entertaining sleuthing than an Agatha Christie novel, for us nerds of course. That really looked like it was too far gone. Fantastic work.
That was a wild ride man. Great Job