Sorry for the off-center video while testing the chips from Machine 2. I just noticed it and can't fix it now because UA-cam doesn't allow you to re-upload a video without changing the URL and losing all the views/watched hours. Chalk that one up to my unfamiliarity with DaVinci Resolve.🤮
@@YARC-1981 the last chips I ordered from Commodore before they closed were the 6581 ARs, I still have a couple left, They were tested when I got them and retested a couple years ago, other than that they have been hiding in an anti-static container
Thank you, Donald. Yeah, I thought I'd get the time-consuming and slightly less engaging part out of the way so we can get straight to the diagnostics and (hopefully) repair on the Live. Looking forward to seeing you and everyone else Sunday.
250466. Board is a great Board. If black screen guaranteed it is ram. If main mos chips are good. However they aren't 4164 16 pin chips, they are 18 pin 41464:) and those boards tend to have pins bent slightly underneath, so a little more tricky to desolder. I heat and straighten pins with soldering station and presion screw driver. Definitely like u said, power switch or something first. Sorry for rambling on. I'm excited. I have a couple boards on the way myself:) prey the vicII and sid is good. Dull fall and winter months are almost here. Just love em. Again sorry for rambling on.
Crap, you made me panic. I forgot about the 41464s. I had to run up to the lab and see if I had any in stock. Turns out I do have 5. They're not tested, but hopefully at least two are good if the RAM in the C is bad. Yeah, I've run into the bent pins before. I saw the same thing when I worked for a company that built control circuits for industrial equipment. If the blade in the pin trimmer was dull, it would bend the pins while cutting them in advance of going through the wave solderer. My Wiha chip lifter has a notch in the end that I often use to loosen pins after desoldering them. It also does an excellent job of straightening the bent ones. Ramble all you want. I'm not bothered. :)
That buzzing sound sure is an telltale sign of an faulty SID chip, at times the reason for an black screen can be pretty simple such as an faulty SID. Recently i acquired an nastily yellowed C64C iam pretty sure it has the 250469 motherboard inside.
I was so deflated when that R4AR started buzzing and wouldn't let the ZIF machine boot. I think I only have one good R4AR in my entire collection right now. I refuse to pay ebay prices for them. At least the ArmSID's out there. It's not AS good as a real SID, but it's definitely closer than any of the other modern replacements. Good luck with the C64C. Are you planning to retrobright?
That board would surely benefit from retrobrighting, it is very unevenly yellowed. Your C64C looks almost new compared to mine in terms of yellowing. I have just opened it up for the first time and yes it has the 250469 board inside. Now i need to power it up to see if it works.
I don't like to do that with C64s. There are already enough issues with jail bars and other video artifacts without introducing switching noise. I'll stick to the linear regulators. Thanks for the suggestion, though.
My condolences on the bad SID chips... Erm - one question that might make a difference - the 8580 and the 6581 need different external capacitors for the filters. I wouldn't be surprised if the 6581R4AR also requires different caps and might sound fine in its native machine. Might be worth a test before binning them (even if the caps are the same).
I never bin my dead chips. I keep them in a Dead Parts container. In fact, the three defective chips I found (2xSID & 1xKERNAL ROM) are still sitting on my workbench. So yes, I can check that with the R4AR from the 64C. If you're on the live, please remind me once we get that machine otherwise working and I'll do just that. For what it's worth, in all the videos I've watched about repairing C64s, I've never heard anyone else suggest that this might be true of the R4AR. I knew that about the 8580, but it didn't even occur to me that the 6581R4AR may behave similarly. The other dead R4AR was the one in the second machine that just caused a buzzing noise and wouldn't allow the ZIF machine to boot at all. That one's definitely kaput. I don't know if it means anything, but my ZIF machine was originally PAL. I converted it to NTSC because that was going to be the majority of the C64's I'd be working on. It's remotely possible that I missed something in the conversion that affects SID playback. If so, it's possible the wonky SID from the 3rd machine might work when put back in its original machine. I'll try that, too, if you remind me. Thanks for the suggestion and for watching. Hope to see you on the live!
@@YARC-1981 I should be there when you go live. And since the memory in my brain seems to be made by Micron Technologies, I probably forget that I told you already. (I forgot about your bad parts bin already, you told me before) Yeah the buzzy 6581 can only be used to keep your candy warm. I hope it doesn't damage the rest of the circuit as I have a cursed C64 which kills SID chips - they work fine for an hour or two, but as soon as you go to the bathroom, you come back, it buzzes and smokes (no joke). Since I ran out of 6581s and replaced it with an 8580 (including 9V regulator and filter caps) and it still happened, the problem must be somewhere else. I like when a dead machine has just a dead ROM. They're so easy to replace.
Or PLA. They're so predictable as failure points and, these days, cheap and easy to replace (PLAnkton, PLAdvance, PLA 20V8). I even just ran across a guy in Germany who claims to have found a cache of 1000 Philips PLS100's (Philips version of the Signetics 82S100 programmable logic array) and got them programmed as PLAs. I ordered one (to see if it's a scam) and, if genuine, I'll be ordering a bunch more. He's already sold >200 of them, so I'm not the only person who noticed him. Even with international shipping, each is < $20 US, which puts them not too far off the price of a PLAnkton.
@@YARC-1981 Through two workshop clearouts, my local arcade museum got ONE 82S100, presumably blank. Can't be 100% sure as there are a lot of color TV jungle ICs, some of which were stated to be programmed for a certain make and model.
The Signetics 82S100 I found in the third machine was the first one I've ever seen "in the flesh", so to speak. I've always heard that they and their Philips counterparts were extremely reliable. The one in machine 3 didn't let me down.
A long board in a C64C, that must be somewhat rare, isn't it? Maybe one of the first production of the slim cases, and Commodore just put a left over longboard in it, or somebody swapped it for some reason?
Commodore made the cases compatible with the long boards, so I assumed that was their initial intent. The bottom shield for the short board had to be extended to allow them to mount into the C case bottom. I always assumed the first generation of the C had the 250466 in it and future generations switched to the 250469.
@@YARC-1981 I have never seen a C64C with a long board. But yet, I am across the pond, in the lands of PAL Commodores, maybe they were only made and sold in the USA, very possible.
Sorry for the off-center video while testing the chips from Machine 2. I just noticed it and can't fix it now because UA-cam doesn't allow you to re-upload a video without changing the URL and losing all the views/watched hours. Chalk that one up to my unfamiliarity with DaVinci Resolve.🤮
thanks for another great video
You're most welcome and thanks for watching and for the compliment!
@@YARC-1981 the last chips I ordered from Commodore before they closed were the 6581 ARs, I still have a couple left, They were tested when I got them and retested a couple years ago, other than that they have been hiding in an anti-static container
@@MrLandphill I envy you. I love how those sound. Too bad neither of these were working correctly.
Sweet video:) very smart idea doing the prepping video. See you on Sunday. Can't wait and take care
Thank you, Donald. Yeah, I thought I'd get the time-consuming and slightly less engaging part out of the way so we can get straight to the diagnostics and (hopefully) repair on the Live. Looking forward to seeing you and everyone else Sunday.
250466. Board is a great Board. If black screen guaranteed it is ram. If main mos chips are good. However they aren't 4164 16 pin chips, they are 18 pin 41464:) and those boards tend to have pins bent slightly underneath, so a little more tricky to desolder. I heat and straighten pins with soldering station and presion screw driver. Definitely like u said, power switch or something first. Sorry for rambling on. I'm excited. I have a couple boards on the way myself:) prey the vicII and sid is good. Dull fall and winter months are almost here. Just love em. Again sorry for rambling on.
Crap, you made me panic. I forgot about the 41464s. I had to run up to the lab and see if I had any in stock. Turns out I do have 5. They're not tested, but hopefully at least two are good if the RAM in the C is bad.
Yeah, I've run into the bent pins before. I saw the same thing when I worked for a company that built control circuits for industrial equipment. If the blade in the pin trimmer was dull, it would bend the pins while cutting them in advance of going through the wave solderer. My Wiha chip lifter has a notch in the end that I often use to loosen pins after desoldering them. It also does an excellent job of straightening the bent ones.
Ramble all you want. I'm not bothered. :)
Lol. And thanks bud:) 18 pin sockets too? Lol. Only 2 ram chips in those boards same as 250649
@@donaldblakley6796 pretty sure I have the sockets.
So many C= goodies and even an 250466 motherboard. Lovely!
Thanks!
That buzzing sound sure is an telltale sign of an faulty SID chip, at times the reason for an black screen can be pretty simple such as an faulty SID. Recently i acquired an nastily yellowed C64C iam pretty sure it has the 250469 motherboard inside.
I was so deflated when that R4AR started buzzing and wouldn't let the ZIF machine boot. I think I only have one good R4AR in my entire collection right now. I refuse to pay ebay prices for them. At least the ArmSID's out there. It's not AS good as a real SID, but it's definitely closer than any of the other modern replacements. Good luck with the C64C. Are you planning to retrobright?
That board would surely benefit from retrobrighting, it is very unevenly yellowed. Your C64C looks almost new compared to mine in terms of yellowing. I have just opened it up for the first time and yes it has the 250469 board inside. Now i need to power it up to see if it works.
Rev A or Rev B? (discrete 2114 color RAM = Rev A, color RAM integrated into super PLA = Rev B)
Jam in a TSR-1 2450.
I don't like to do that with C64s. There are already enough issues with jail bars and other video artifacts without introducing switching noise. I'll stick to the linear regulators. Thanks for the suggestion, though.
My condolences on the bad SID chips...
Erm - one question that might make a difference - the 8580 and the 6581 need different external capacitors for the filters. I wouldn't be surprised if the 6581R4AR also requires different caps and might sound fine in its native machine. Might be worth a test before binning them (even if the caps are the same).
I never bin my dead chips. I keep them in a Dead Parts container. In fact, the three defective chips I found (2xSID & 1xKERNAL ROM) are still sitting on my workbench. So yes, I can check that with the R4AR from the 64C. If you're on the live, please remind me once we get that machine otherwise working and I'll do just that.
For what it's worth, in all the videos I've watched about repairing C64s, I've never heard anyone else suggest that this might be true of the R4AR. I knew that about the 8580, but it didn't even occur to me that the 6581R4AR may behave similarly.
The other dead R4AR was the one in the second machine that just caused a buzzing noise and wouldn't allow the ZIF machine to boot at all. That one's definitely kaput.
I don't know if it means anything, but my ZIF machine was originally PAL. I converted it to NTSC because that was going to be the majority of the C64's I'd be working on. It's remotely possible that I missed something in the conversion that affects SID playback. If so, it's possible the wonky SID from the 3rd machine might work when put back in its original machine. I'll try that, too, if you remind me.
Thanks for the suggestion and for watching. Hope to see you on the live!
@@YARC-1981 I should be there when you go live. And since the memory in my brain seems to be made by Micron Technologies, I probably forget that I told you already. (I forgot about your bad parts bin already, you told me before)
Yeah the buzzy 6581 can only be used to keep your candy warm. I hope it doesn't damage the rest of the circuit as I have a cursed C64 which kills SID chips - they work fine for an hour or two, but as soon as you go to the bathroom, you come back, it buzzes and smokes (no joke). Since I ran out of 6581s and replaced it with an 8580 (including 9V regulator and filter caps) and it still happened, the problem must be somewhere else.
I like when a dead machine has just a dead ROM. They're so easy to replace.
Or PLA. They're so predictable as failure points and, these days, cheap and easy to replace (PLAnkton, PLAdvance, PLA 20V8). I even just ran across a guy in Germany who claims to have found a cache of 1000 Philips PLS100's (Philips version of the Signetics 82S100 programmable logic array) and got them programmed as PLAs. I ordered one (to see if it's a scam) and, if genuine, I'll be ordering a bunch more. He's already sold >200 of them, so I'm not the only person who noticed him. Even with international shipping, each is < $20 US, which puts them not too far off the price of a PLAnkton.
@@YARC-1981 Through two workshop clearouts, my local arcade museum got ONE 82S100, presumably blank. Can't be 100% sure as there are a lot of color TV jungle ICs, some of which were stated to be programmed for a certain make and model.
The Signetics 82S100 I found in the third machine was the first one I've ever seen "in the flesh", so to speak. I've always heard that they and their Philips counterparts were extremely reliable. The one in machine 3 didn't let me down.
A long board in a C64C, that must be somewhat rare, isn't it? Maybe one of the first production of the slim cases, and Commodore just put a left over longboard in it, or somebody swapped it for some reason?
Commodore made the cases compatible with the long boards, so I assumed that was their initial intent. The bottom shield for the short board had to be extended to allow them to mount into the C case bottom. I always assumed the first generation of the C had the 250466 in it and future generations switched to the 250469.
@@YARC-1981 I have never seen a C64C with a long board. But yet, I am across the pond, in the lands of PAL Commodores, maybe they were only made and sold in the USA, very possible.
Yep, possible.