Mysterious Commodore 64 Repair & Chip Socketing | see description

Hey guys and welcome back to Retro Recipes So, here I have my Commodore 64 which I recently refurbished But.


Hey guys and welcome back to Retro Recipes So, here I have my Commodore 64 which I recently refurbished But there’s one little problem that’s been niggling away for the last year or two And popping up every now and then So once in a while when I boot up the machine, the basic display will look like this There are characters, they’re either missing or have turned the same color as the background Now, that would imply to me that the issue was the color RAM Chip Which is a fairly common fault with these machines I mean, there’s been 35 years after all so I forgive it But another issue that I’ve seen, which may be related, is when I play some games For example, this one Alice in Videoland You can see and what kind of an evil entity could give Alice spots like this Don’t think she was even teenager at that point Now, that could, again, be the Color RAM Chip But there’s only one way to find out for sure And that’s to run some Diagnostic Test Cartridges So, that’s what I’m gonna do okay Okay, so, I’m using EasyFlash 2 Cartridge Which enables me to run a series of different diagnostic cartridges from one place So, let’s start off with Diag C64 So checking through the screen RAM at the moment That’s okay RAM Test1 Also, okay! RAM Test2 Also, okay Now, the PLA Seems to be okay, OK, PLA Now, the color RAM Now, this is my suspicion It says it’s okay! Now, one of these strange things is …(random SID sound) ..being interrupted by SID here Mute, you! One of the strange things is, I have ran this Color RAM test before and it’s come out bad So there’s either an intermittent fault, or it could be temperature related I did have a bit fit the tiny heat sync to the Color RAM Chip As you may have seen on my Refurb Video and that may have been helping things Anyway, let’s try a different cartridge The other one, not Diag C64 but C64 Diag, Ehh.. easily confused Zero Page, OK. Stack Page, OK. Color RAM, OK.. okay. 64-K RAM.. Everything looks okay Keyboard Joystick, BAD U1 Now, those eagle-eyed viewers who saw the previous test would have spotted an issue with U1 The other cartridge, so let’s just flip back to that Okay, so as mentioned It’s showing U1 and U2 as being bad Also, U18, which is the SID Chip I haven’t had any problems with sound But U1 and U2 are the CIA Chips As you may know, it’s actually the same chip in both sockets And they are inter exchangeable So. U1 does seem to be on number one of it Which is probably why it’s called U1 Let’s get a final, 4th opinion here from DeadTest A very ominous sounding cartridge With an ominous font Zero Page, OK. Stack Page… …the suspense is going to make us dead Well, it’s okay What’s happened?? Hellooo? So, Color Ram is okay Sound test is going on silently, it’s muted right now Well, this one looks okay too For me it’s looking like U1 is what we’re gonna have to replace We can start with that just for completeness and cuz it would bug me, otherwise I’m gonna also replace, U2 Or at least socket U2, so they both look the same I don’t think we have to worry about the Color RAM just yet So let’s get on with the repair! I will see you on the workbench (German accent) Hi! It’s Jan Beta It’s not really! It’s Perifractic! Alright, so let’s get unscrewing this machine Okay, so these are U1 and U2 Not like the band These ones don’t make excellent music You’re confusing that with the SID chip But they are marked here, U1, U2 CIA Chips, in other words, and that stands for Complex Interface Adapter These are responsible for interfacing with the I/O ports, the joystick ports, that kind of thing But it does mean they’re very susceptible to static electricity, damaging them So, if you were to have static discharge come from your fingertip, like Harry Potter or something, and you were to touch maybe the user port or joystick port particularly, you could damage the chip So that’s why it’s a very common fault So let’s turn the board over and see if we can desolder these little things After we’ve unscrewed all of the screws Now, I have static discharged myself, and that’s something that I do regularly throughout the process You don’t want to introduce yet another fault having just cured one So, I’m gonna moisten my sponge (chuckles) Please hold the line Okay, the sponge has been moistened So I’m gonna do a few things with the soldering iron just to prepare for this, to make sure that we get the best possible heat conductivity That’s gonna enable us to easily desolder these pins Here, indeed, is my soldering iron This is the one I recommend, The X-Tronic 3020 It heats up in seconds, it’s pretty amazing! So, if you look at the tip of the iron, it’s a little dirty So I have here some TIp Tinner Then I’ll put a link to this stuff, as well as a link to this soldering iron, below I do find this invaluable Some people say you don’t need it But if you can look at how beautifully that has burned away any corrosion and prepared the tip for soldering Yeah, really it can’t hurt at all I find that it makes things better Then I’m gonna clean the tip, just to remove any excess And what you could also do between those, is clean it on the sponge Now, we introduce the solder sucker So this you just activate the pump, push this button, and it sucks the solder that is currently melted under the soldering iron, into itself So let’s get started So now you can see instantly that that has desoldered this pin Now something to keep in mind when you’re working with this older solder, pardon the rhyming slang there, is it can contain and probably does contain lead Now people say this doesn’t evaporate or melt until several hundred degrees fahrenheit However, just to be careful, I’ve opened the window and turned on the fan So, apologies if you hear any background sound And just to make this a little easier.. I’m going to use a Flux Pen So, this is good for reworking solder And it helps with the transfer of heat and also removes oxidation To push down just to get the flux going There it is Just draw it on there I’m actually going to turn this around because the pins seem to be favoring one direction Not a band that I like But in this case, it’s going to help us to heat up in the angle that the pins are actually facing See how those are coming out of the holes really easily And 40 pins to go Just now and then when the ease is starting to fade, I am retinning the tip of the soldering iron Just to aid in that conduction again And now and then you have to remove the sucked solder from this sucker Sometimes if one is being stubborn, you can heat the pin and then instead of sucking with the sucker at an angle, you can just let go and suck it up straight like that It’s pulled a lot of solder up through there So I’ll keep tinning.. keep sucking We do have some traces here, so we have to be super careful around this area So I’m gonna switch to a smaller, finer tip So I’ve tinned the tip and you can see the corrosion, any oxidation bubbling away there And a little more tin And we will get back to work Very fast sucker, needs a clean-out Yeah Melt. Suck. Whoa! That’s almost too much Interestingly, the sucker was then tinning the soldering iron for me Not sure if that’s a intended behavior But we will keep removing these little parcels of leaded 1980’s solder So we’ve got our system down now It is a smaller tip and fuller suction That was the key If any of you are a little nervous about soldering or would rather not do this but want some mods or repairs done, suppose now’s as good a time as any, as I mention that I do offer repairs and mods And you can (coughs) while I choke on the lead You can find the contact info under this video in the description And see if this thing wants to come out And for that I’m gonna use the specialist tool, which is the chip removal tool Let’s just hope we’ve desoldered the correct chip There she is! Came out in one piece No bent legs These are so well desoldered, you can actually sell this If it wasn’t faulty, in this condition So Next up, we want to socket this area My motto is if it looks good, it probably works good Just about putting care into things And treating things with the respect that you would want them to treat with you with And if I was ever refurbished by a Commodore 64, I would want it to take some care Particularly with my hair Okay, now we have our clean, shiny Actually. Shiny. That reminds me.. We’ve got some alcohol wipes here There we go Now, next up lil box of treats here Candy! Not really We just need a 40 pin DIL socket otherwise known as a DIP socket If you see them called different things sometimes, some people say it means exactly the same and some say that DIL was originally a ceramic type Whereas DIP, P meaning plastic Not sure what ‘L’ stood for Leprechauns! I mean, I don’t know So we should be able to just drop this in to our nicely desoldered pins As the notch is there to help you translate where the notch of the actual chip goes So we’ll get that right I’m just soldering that one and this one first cuz that’s gonna help hold things in place Check everything’s looking nice on this side Got to the end and I was like, ‘how did that get soldered?!’ I did it earlier Remove any excess flux Then we have our soldered U1 CIA socker Now, we have two options here We could, as I said earlier, unsolder this too and put a socket in However, there’s always the chance you break something If it ain’t broke, don’t try and fix it On second thoughts.. I’m going to go to my stockpile of spare chips And see if I have a matching replacement here This is a 6526, it was manufactured in week 29 of 1983 And it’s Revision 4 And.. Look at that! Slightly earlier, 6526, Revision 4 Now, these are known to all be working And this one is the one that diagnostic test said was faulty So, what we can do.. is pop this in the socket, and return to that diagnostic test and see if things still report errors Or if the problem is fixed So once you get all the pins in and just double-check they’re all lined up, just firm pressure straight down That is now a socketed CIA chip Let’s go try it out! Okay, so, I only connected the board and the keyboard Let’s go try it on and turn it up! Try it out and turn it out.. turn.. let’s turn it on..and try it out Okay. That’s a good start! C64 Diag Interesting Bad U1 We could have two bad chips Or there could be an error somewhere else Could even be U2 U1 and U2 still reporting bad here Let’s try Dead Test (sneezes) Excuse me Think I’m allergic to death Well we’re still getting the same results So, unlikely, though, it is, I’m gonna replace the U1 with the second spare that I have Just in case the first spare was faulty Bad U1 So that’s three chips we’ve tried Well, I think the only thing to try now is switch out U2, as well And see if we were getting some sort of interplay of the errors there Wish me luck?! Okay, so I now have two socketed CIA chips Looking very neat and tidy in there So let’s give them a try Bad U1 That is strange! U1 and U2 still showing it’s bad So, what I’m gonna do is switch out the U1 and U2 that were originally in there, into the alternate positions So, U1 and U2 will become U2 and U1 Just a lot easier now that they are socketed C64 Diag Yep Bad U1 So that tells me that all the other tests are gonna result in U1 and bad U2, as well Basically nothing’s changed Now on the plus side, we now have some socketed chips, which we didn’t have before So that’s useful and looks nice, and if we ever have to change them in the future for a real reason It’s gonna be easier to do However, you can see just under the SID chip there, that I have my heatsinks on my Color RAM Chip You can wear it like a scarf and just point out, ‘this is the Color RAM right here.’ Now what I’m going to do.. because my original suspicion was that the Color RAM was giving issues, especially because of the nature of those character.. garbage characters.. and the fact that I get one time see a Color RAM error on one of those cartridges Just gonna swap that out, socket it and see if that resolves our U1 issues, at least And because all normal games, apart from that Color RAM issue, do run properly and correctly And.. Since I put the heatsink on the Color RAM, I’ve not seen that issue return So I think we may have.. nothing wrong with our U1, U2 CIA Chips and a Color RAM that doesn’t like to run hot So, I’ll switch it out, and we’ll see what happens Here’s our Color RAM First thing we have to do, course take me heatsink off And we do have the replacement Somewhere.. Here it is. You can get this and lots of other replacement parts from Retroleum I’ll put a link below the video Okay. Now another good technique just before turning the board over, is to push each pin and just make sure that they spring back If they do, that means they’re probably free Now and then we get a little gift from the solder sucker See if we can get this sucker free Much, Oh! Much easier than the CIA chips A notch at the top Beautiful! Can start soldering the opposing corners That’s just my little technique to keep it in position I like.. it’s nice! Being with the new Color RAM, no heatsink required There it is! Okay Well this board is certainly, if nothing else, had a socketing, riveting experience Let’s go try out this new Color RAM! Well, at least the new Color RAM is okay, as well This one is, hopefully, less susceptible to overheating Bad U1 U1, U2, U18, all the same. What I will do however, is now test Alice in Wonderland and see if she still has acne You look good, Alice! Now, I did get some issues when I connect with joystick No such issues No such issues Well, while Alice loads, I think we’ll call this a minor success And there’s still a bit of a mystery Definitely the Color RAM issue is not currently happening you can say that much for sure! And we have some nice socketed, sockets As for you Alice, will leave her in her Wonderland Maybe I’ll help her find her way out If you have any ideas what could be causing the U1/U2 issues Apart from Bono Then let me know drop me a comment below Maybe we’ll end up doing another video if there’s something interesting that we can try Until then, I’m just going to enjoy all the games that seem to be working And please like, subscribe, and share this video if you want to see more like this! Until next time, Cheerio!

66 thoughts on “Mysterious Commodore 64 Repair & Chip Socketing | see description”

  1. Is it possible that not having the test harnesses hooked up is causing the issues with the U1, and U2 testing results? It's been a while since I've had mine hooked up to check a board. Perhaps someone else will remember?

  2. Nice video.  You did a great job desoldering and soldering in the socket.  I appreciated how you captioned the part where you removed the chip with the chip puller to use gentle pressure.  I learned the hard way on one of my first desoldering repairs that if you have to pull it out with too much pressure you will likely lift a trace or a pad.  I did exactly that and ruined a board.  Well when my skills improved I actually repaired it but still it was a hard lesson to learn.  Now I make sure those suckers practically fall out on their own after desoldering.  😉

  3. Hi, if you run Diagc64 or C64Diag you need special cable adapter hooked up to the user port and joystick port and keyboard port. If you don‘t do this you aleays gets bad U1 and U2 chips. Just look this specs up in the internet. theyvare really easy to build.

  4. Nice video. I like your Jan Beta impression. I wasn't aware of your channel. Glad I found it — now I have to play catch-up. Subbed.

  5. Thanks a lot for the video. You are including more in the description of the video than I've never seen, with links to whatever.
    I wish I had seen your recomendated products, as I recently ordered a multimeter for about the same price (I hope mine will be as good).
    I see you don't like to spend much, just like I do. I use your same desoldering pump (BTW it costs 1€ in China with sending). What I want to comment is that I'm bored of that sucker (ahem). Sometimes it isn't so easy to desolder things with it, but I also don't want to spend much in a desoldering station, neither I have room for it. So I've just bought this from Ebay, it seems to be a nice solution https://www.ebay.es/itm/322823598317

  6. If you want protection against lead you should wear properly treated working gloves, lead penetrates the skin quite easily so touching it is enough to transfer it into your body. Ventilation is still good because of alcohol/flux fumes and some other fumes which can be formed are still bad to get into the lungs.

  7. I just run the same diagnostic tool and my 100% working C64 reported bad U1. I have to get that C64 diagnostic cable set.

  8. Thanks for watching! What's the weirdest fault you've had? Let me know below!

    I know that the lack of a loopback cable can also cause the U1/U2 errors, but that's usually just U2. As connecting the joystick was causing the Colour RAM issue, and that is usually a CIA error, I decided to switch them anyway. Your friend in retro, Chris aka ԹҽɾíƒɾɑϲԵíϲ

  9. since you do retro repair … this is just a suggestion.. but when desoldering its a good idea to heat all the joints and add a bit of leaded solder to each joint before desoldering… it helps with the melting and flowing of the solder…

  10. as mentioned in one of your other vids when i repaired my c64c i replaced the 6526 with 8520 from an a500 – worked fine. only difference between the two is the 6526 runs at 1mhz where the 8520 runs at 2mhz (not its not overclocked), the 64 just runs the 8520 at 1mhz. also subbed as well, great content and great presentation.

  11. Hello, why did you not use de dongles that you need with the test, normal you need to plug in a kind of dongle's in the joystic ports (basic thay make a crosslink between them to test the ports.
    here is a exampe of that dongle/ port test https://www.ebay.com/itm/Commodore-64-64C-SX-DX-128-128D-128-DCR-FULL-Diagnostic-Test-Harness/161541633142?hash=item259ca1b476:g:c7UAAOSwgJlbEbNN set without it it wil alway say bad cassette port, serial, and als U1 due to to joystick do not return the right values. ( ps de link is to a ebay seller not me. and its out of stoke but if you google a little there is a info about how to make the cable/dongle your self.

  12. Just found your channel and subbed, weirdest fault i've had is the Saga Master system Mk1 I’m working on at the moment, graphical glitch and i've changed all the usual suspects and its still glitching.

  13. I can tell you're using that horrible lead-free solder, since all your new solder joins look dirty and dull. Still excellent job overall 😀

  14. I had a couple of really strange faults.
    One fault was a wave across the screen like the crowd wave at football/cricket matches. It was an early version motherboard using several chips inside the tin can at the front. The fault was a bad 74LS629. I sent the info in to the C64 fault repository and you can see a video of the fault here…
    https://derbian.webs.com/c64diag/fault.htm?id=u31_4
    Second one was the 1541 motor spinning all the time and the FDD wasn't faulty. it was a transistor that buffers the reset signal on some versions of the C64 motherboard and this was one of those versions. Changing the transistor fixed the problem. unfortunately I found out later that when the fault happened (shorted transistor) it blew up my SD2IEC that was plugged into the IEC port. I tossed it because I figured it wasn't fixable and they were too expensive to re-buy. Even worse I found out a few years later that it wasn't a special custom device it was made from the open source project at sd2iec.de and was the common ShadowWolf 1.2 version, meaning I could have fixed it by buying a new Atmel microcontroller and re-programming it. But again unfortunately I had tossed it somewhere when it blew up years earlier and had no idea where it was. I turned the house upside-down recently but couldn't find it 🙁

  15. Nice work. I had a job getting my NES going. The 72 pin socket wasn't the problem, someone had been trying to fix it and broke it. They cut the IRQ line on the board and rejoined it but didn't notice they also cut the adjacent line. I soldered a wire in to rejoin it and my game booted. All it cost me was $8 at the thrift store and a little work. I'd say that attempted repair was due to the 72 pin socket and the repairer mistakenly thinking the IRQ line had anything to do with it.

  16. Capacitor replacement? Done that yet? I mean, if you're plugging components in and the new drain is suddenly causing errors…

    That's super weird.

  17. Just browsing through again. Had to comment on the soldering portion of the video.

    I'm more fond of wicking than using a sucker. Reason being is when working on old boards, I've ran into rather nasty incidents where the sucker actually took contact pads off of the board. Wicking is more delicate in this fashion, which definitely matters to retro boards. Simply flux the wick and press it to the desired removal location, and heat with the tip of your gun, dragging the wick very gently across the contact point.. Heated flux and copper wick draws solder towards it like a magnet, into the wick, and offers the added bonus of lowering the risk of contact pad damage.

  18. did you checked the tracks with the magnifier?, it can be as simple as a bad track to hole connection, maybe one oxidated under the solder mask, just in a tiny part, so, interrupting the signal..

  19. That's just regular foam, the static dissipative stuff is pink. So your chips aren't actually known good anymore.

  20. Would I jinx it if it would be the issue with the onboard cartridge slot? Like oxidation on the PCB as that happens from time to time and is very picky about its occurrences ( the life saving breath for old cartridge based electronics thing 😉 ) Based on same way that Easyflash diagnostics interfaces with The Board .

  21. I use a solder pot for getting big chips out. Yes I make bridges if I don’t cover other pins (thank god for Kapton tape) but I hate solder suckers, sometimes they miss a tiny blob of solder in the through hole and you have to hunt down what pin is still partially soldered if you can’t see it.

  22. Something I've found that works quite well for cleanly sucking the solder out of the holes is to stand the board up on edge with a few small clamps, press the tip of the soldering iron to the leg of the pin on the chip side of the board, and suck the solder from the solder side of the board. That allows me to keep the sucker firmly down over the hole while not having to remove heat from the pin. Until I can afford a desoldering pump, that seems to work best. And before you pull the chip out, you ALWAYS want to wiggle each and every pin on the back side of the board with a tweezers or needle nose pliers to make sure they have released from the through hole as much as possible. Even if they all seem to have fully released, there may still be solder binding them to the stop side of the board. Don't just yank the chip out; use a flathead screwdriver to very gently pry the thing up while observing all the pins. If you see any trace or through hole rim start to pull up, stop immediately and use the soldering iron to melt the solder and push the trace back down to the board to minimize the damage. While it's easy to repair a broken pin on a chip, it's a bitch to repair a lifted trace.

    By the way, the diagnostic cartridge is always going to show a bad U1 and U2, as well as other things, when you don't have the full testing cable installed that wires all the ports together. There's a schematic for how to build one. For the portion that plugs into the keyboard pin header, you can make something out of an old IDE ribbon cable.

  23. Alright, that's really weird but in a good way. Having never heard of Alice in Videoland (the game) I poked at Youtube and found a Swedish synthpop band named Alice in Videoland. Good band, in my opinion that is. But totally unexpected. 😀

  24. Do you use dual-wipe sockets to match what C= used to use, or is it just what you happen to have on hand? Generally in rework like this I prefer to use machined-pin sockets as they will stand up to future oxidation better, and they're also easier to remove and reinsert devices – dual wipes that have been seated for a few years can really cling to those pins, especially if the pins were tinned as the leaves of the socket will bite into the PbSn coating. The only thing to "beware" of when using machined sockets being, if you are reinserting desoldered chips, you do need to clean the pins up well.

  25. I think, your solder sucker sucks. I am using the soldapullt for over 20 years now. It really sucks a lot and I like it. I have one like yours, too. But that doesn't really suck. I mean, it is not so great.

  26. I use this smd flux (liquid, like used in the industries). It is pretty cool with solder wick and soldering in general.

  27. Great geek porn dude! every time you say suck it, many nerds have an orgasm!
    Regards from Argentina.
    PS: Fakland islands are ours! give it back!

  28. Gotta say, and don't take this the wrong way, that I often put together a play list of your videos, the 8 bit guy, nostalgia nerd, etc…to fall asleep to. Something comforting about it. Keep the videos coming!

  29. I'm not a 100% sure… but I feel like I've seen someone else have a similar problem. And it ended up not being one of the main chips that was actually bad… but instead, it was one of the 7400 logic chips that handled the address decoding that was dead.

  30. Nice video. Those diag tests are not the brightest. Could be any link in the chain. Well done with the desolder, I never could get on with those manual desoldering pumps!

  31. Aww, this guy is totally 🔥and super sweet! Nerds aren't supposed to be THIS adorable. I especially enjoyed watching him wield that hot steamy tool and all that wick sucking and socket insertions bring much needed handheld joy to my 8 bit stick (…alright, give or take a few bytes )👍. Keep it cuming Peri! …Errr THEM, keep "THEM" coming.

  32. Doesn't the SID work with the CIAs to do the joystick or something? I have a vague recollection they are connected somehow. It's likely possible for chips to mostly work eg. for the SID to produce sound but for it's more obscure functions to not work exactly correctly, eg. stuck bits, etc.

  33. I always prefered wick/braid when desoldering chips like that (unless I have a powered desoldering gun that is). I've seen those suckers suck the pad right off the board if it's in bad shape already. I did get irritated at desoldering stuff and eventually built myself a solder pot. Use kapton tape to cover all the surrounding pins, set the board on the pot, and pull the chip out of the holes, then drop the new chip into place. It does require you to ensure all the pins on the new chip are nice and straight and lined up with the holes or it won't drop in, and don't want to leave the board on the pot for too long.

  34. I also have that manual desolder pump, or suction pump 🙂 – I have mine for years, although it could use a new tip. Many times it got burned so bad I simply removed some of the plastic, so now the metal lead tends to be in the way of larger solder joints. Great video, keep them coming:)

  35. Hi, I wonder if it might be some power issue of some kind so those chips does not work properly cause they got not enough current. maybe a capacitor that broke or almost broke?

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