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The only thing that made sense in my head was that whoever they were, they didn't have the correct size socket and it didn't occur to them to either cut down a larger one or build one up out of two smaller ones. Still not their best option. I would have just waited until I could source the correct sockets. Crazy is right!

Can't wait!

Thanks. I can't take all the credit. It was pretty clean when I got it.

A superpower like that would come in handy. Where I live, we've been going through a drought. The power to make it rain on demand just by taking something to my retrobright setup would have made me look like a local god. :)

Thank you for your feedback. If you don't like my content, may I suggest that you simply don't watch it. No one is forcing you. I'm not an expert and I don't claim to be one. I'm learning and I hope my viewers might be able to learn along with me, or, at least that I might provide them with some light entertainment, even if it _is_ just laughing at my mistakes. But don't let me waste any more of your time.

I never use the original power bricks. When working on a C64 or VIC-20, I use a custom built power supply with overcurrent and overvoltage protection. As for the original brick, if I get one with a C64 I buy, I just gut it and use the case and cables to build a safe one into. The potted components just go in the bin. The electrolytics on C64s are *almost* never the problem. They weren't made during the capacitor plague, though that's no guarantee. 120Ω is the value recommended by most folks who do these repairs and matches the schematics, but yes, 75 or 100Ω might give a little brighter picture on composite, though it would leave the luma signal a little out of spec for an s-video output if I wanted to do that mod, too. There are other ways to make the reset mod that I've seen, but this seems the most straight-forward and easiest to reverse if you ever want to put the board back to stock configuration.

@@YARC-1981 -- On another channel, the tech measured and found that even 120 ohm gave voltages on the low side of the specs and determined 75-100 ohm for the specific machine met the specs better. But then, I think it used the oldest VIC-II. I've seen other types of machines where aging filter capacitors on the power rail contributed to lower voltages at the other end of the board. That was the case on an arcade game. The machine was running a little on the unreliable side and changing the large filter caps helped. Of course, they don't change every electrolytic capacitor. For instance, on the solenoid driver board, they usually leave the one in the HV circuit for the plasma alone. It usually doesn't need replacing, and sometimes the machine is upgraded to not even use that rail. In that case, the 5V rail should likely be beefed up a little to accommodate slightly more load there (since an LED display kit was installed) What many don't realize is that if electrolytics test fine on a "capacitor tester," they can still be marginal. In fact, failing ones may test even "better" than a new one. To test this, you can put a resistor across even a new capacitor and use a capacitance meter. It may read "too high" when the resistor ensures it isn't working as good as it could. Those meters rely on a math formula and apply it to the rate of charge. That is like measuring how long it takes to fill a bucket with a hole in the bottom with water and concluding the 5-gallon bucket is a 7-gallon bucket because it fills at the rate of one. I agree that these were before the capacitor plague. It also depends on who made them. For instance, you can likely take a modern Chinese-made PC PSU, change all the capacitors (even brand new), and make it more reliable. In that case, maybe change the fan motor too (or at least disassemble and lubricate it). Some modern switching PSUs use diodes in interesting ways where they are more critical such as using them in series. I guess that is to interface between the rare few ICs that use higher voltages to drive 3.3 - 5V ICs (since the forward drop is much higher). So they might not test as shorted out but still might not be working. And I've seen regular diodes used as low-voltage Zeners too such as wiring two of them in reverse piggyback configuration to simulate a low-voltage MOV in an audio circuit as a crude gain control. (Then it won't go past 0.6V in either direction.) Then with other things made in budget conditions or even sweatshops, the issue is not so much the quality of the components, but more the care in which it was assembled. You may, for instance, be able to take a mechanical wristwatch purchased from Alibaba or similar, disassemble it completely, do a full servicing, clean and inspect everything, burnish any rough edges on the pivots, lubricate it (using common sense and other companys' service guides if you can't find any for that one), and adjust it for better performance and longevity. They may use the same process to make the parts as more reliable companies, but they might not even lubricate or adjust them properly. Sometimes with such watches, you can also make upgrades if you have the tools and know-how. An example would be replacing any metal bushings with jewel bushings.

@@PlumGurly With regard to the 120Ω resistor, I believe you're referring to Adrian's Digital Basement. I've seen that video and yes, he determines that a lower value resistor gives him a better result on composite video. He never tried to get s-video out. What specific capacitors on the board are you concerned about? If you're referring to the large electrolytics used in the regulation circuit, those are only relevant to the +5V and +12V isolated power going to the VIC-II and the SID. They don't have anything to do with the 5V rail going to all the other components. That rail is supplied by the external power brick, so changing those out would do nothing for the voltage at the other end of the board even if they were faulty or marginal.

@@YARC-1981 -- In the context, you can tell I was speaking about the power capacitors. You mentioned the voltage being low by the ports. I was just explaining how that could be the case. You said it wasn't and had moved on. I just described how that can be the case with other types of machines.

There are four different major revisions of the C64 long board. The KU-14194HB and the 326298 have the SID and PLA side-by-side. In the 250407, the PLA is next to the 6510 and the SID is in front of it next to the VIC-II RF shield. Finally, the 250425 has the SID next to the 6510 and the PLA next to the VIC-II shield. All you really need to remember is that the PLA is ALWAYS U17. And yes, this has caught me on at least one occasion when I put them in the wrong sockets and ended up blowing out a PLA with 12VDC. Kicked myself for quite a while about that.

Thank you. I appreciate that.

Thanks, Bora! I'll probably be swapping an original 6581 SID into the board eventually (along with the ceramic 6567R56A and the ceramic 6510 from machine 10 and a few other more period-accurate chips) at a future date, so the cap replacement will absolutely help there. I used the ArmSID to get the machine up and running.

Plastic packages came later, during 70's and very early 80's, almost all ICs (RAM, Logic, etc) were in ceramic packages.

I've only ever seen pictures of ceramic 6510's, so it was a surprise to me, too. There may be more C64 repairathons if I can get enough non-working machines. They're becoming harder to come by. I assume that has something to do with how many of us are already out there repairing them. Watch around mid-2025 to see if I've managed to collect some. :) Thanks for watching!

Which is why it surprised me that this one had an '86 date on it.

Me either... I thought it was a ceramic vicII myself

I've known about the SixtyClone for quite a while, but I'm more tempted to build up one of bwack's replicas, probably the 250407. Keep watching around the end of the year to see what I end up with. Thanks!

Much appreciated, Donald! See you in the next one.

I can't imagine I had much to offer you, Rudy. You already seem better informed than I am. But high praise. Thanks!

@YARC-1981 We know, learn, and share. That's part of the fun of retro computers. Thanks for a great channel!

You're very welcome. I don't know about future C64 repairathons (broken C64s are getting harder to come by and more expensive), but there's definitely a lot more content to come. Thanks for the watch and we'll see you in the next one!

My pleasure!

There will always be more broken C64s because: 1. They made so many of them 2. Commodore always spent as little as possble on quality.

Surprisingly, broken ones are getting less and less common and more and more expensive. I think there may be too many of us out there fixing them. But you're right about the reasons. Thanks for watching!

Thanks, Mark. I'll get around to the regulator mod. I just didn't feel like drilling right then. It was late at night. Your s-video mod is easy enough and I may do it, I just don't have a cable built that would work with it. That's what held me back there. I really hate building cables :)

​@@YARC-1981 100%. Building cables is my least favourite thing

Thanks. I don't really think I'm doing anything noteworthy. I just enjoy it. If it keeps a vintage machine off the scrap pile, well that's just a bonus.

And boy have I been getting an education. Glad you're enjoying. Thanks for the watch and the feedback. I really do appreciate it.

If I'm honest, I'm probably not the best person to answer. I've tried several "modern" loading mechanisms, external tape drive, TZXduino, loading via a Bluetooth receiver, the CPCDandanator and the DDI5. I liked the DDI5 the best, but there are probably other solutions out there like the one you mentioned that I've never used and am, therefore, unqualified to evaluate. Thanks for watching.

You're welcome. And thank you for watching and for the feedback.

Thanks, Donald. I appreciate that. Also glad I'm not the only one to experience the diode issue. :) See you in the next one!

I left mine for a couple weeks , then got the schematics like u did... I plugged in a known working datasette I have, I powered the 64 on, and it ran continuously. I replaced and socketed the 6510.. no change.. then I replaced 1 of the cias and socketed... can't remember which one now... still no change. Then I'm like.. I don't know.. I took that zener diode off a very bad board and soldered it in the other board and.. it just freaking worked.. I was crazy happy. 😆

Yup. Fix one and another appears. Thanks. And thanks for watching!

It's basically this one. I think mine may have been an earlier model. I have the one Adrian Black reviewed. www.amazon.com/Hantek-Handheld-Oscilloscope-Multimeter-Multifunction/dp/B07PWZV4XJ/ref=sxin_16_pa_sp_search_thematic_sspa?content-id=amzn1.sym.e8df51fd-b950-4a2f-bfb3-8dbdae6ffa25%3Aamzn1.sym.e8df51fd-b950-4a2f-bfb3-8dbdae6ffa25&crid=QTD3XNYPU95M&cv_ct_cx=handheld+oscilloscope+multimeter&dib=eyJ2IjoiMSJ9.x1C9-luR7EiqHBQ7rBkIRLtgWBAfby0YF7WvmxiysMh5ugjBFniYQ0aeBSayai1hsDOcbCQhbTRoLRhJG2bMJg.DgAJakeAlgfmSb0dWZbriDIhBwkEauOa6XIfsXJ4aQo&dib_tag=se&keywords=handheld+oscilloscope+multimeter&pd_rd_i=B07PWZV4XJ&pd_rd_r=cf817997-acba-4896-b6d8-04f293b30e54&pd_rd_w=bEr8F&pd_rd_wg=bHbCb&pf_rd_p=e8df51fd-b950-4a2f-bfb3-8dbdae6ffa25&pf_rd_r=JB79FG72AE2C6RHD0VBC&qid=1721500912&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sprefix=handheld+osc%2Caps%2C93&sr=1-5-e20883f9-9d72-4842-a3e6-e1cd54d2b900-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9zZWFyY2hfdGhlbWF0aWM&psc=1

Thanks, Rudy! I really appreciate you.

I didn't know that. Thanks. I'll look into it.

And as for the deadtest i use the kinzi version which shows you different colors when starting the mem test. Just google deadtest kinzi.

I've heard of that one, but haven't downloaded and burned it to an EPROM yet. Thanks.

@@YARC-1981 it helps a lot seeing that the mem test is running. Because a dead pla also tends to show a black screen.

I'm happy to take any specific recommendations you may have for improvement. As for the ZIF board, I don't like to use it that much for three reasons. First, not everyone out there has a known-good board with sockets fitted that they can use as a test bench, so if one of my goals is to show folks how they can repair their own machine, it's better to try other diagnostic methods first. Second, I like to see the actual fault, which you don't get if you just pull every IC and test it in another machine. Third, not every machine I work on has all the ICs socketed and desoldering a chip just to test it in another board without specific indication that it may be faulty is hard on both the chip (if its good) and the board itself. As for drifting away, there may be two causes for that. First, I usually do these in the evenings and as it gets later I lose focus. I'll try to work on that. Second, I start getting into areas where I'm not as knowledgeable or as confident, so I slow down to try to understand what's happening and what should be happening. That's a learning curve and is probably unavoidable until I get better at what I'm doing. Thanks for watching and for the feedback!

@@YARC-1981 if those are your goals/challenges, then let us assume a different premise: Most people without a second c64 at hand most likely don’t have an oscilloscope, a minipro programmer, a ram tester and/or a test cartridge either. Therefore it may be a more reasonable path for teaching repairs is with a multimeter and a logic pen. Perhaps following the sams repair guide or the c64 maintenance manual and/or the visual troubleshooting screens from Ray Carlson. My 2 cents as suggestions. Thanks for sharing your content. I liked and suscribed

Thanks for the like and subscription. There are many paths to the same result when troubleshooting and repairing computers. I've shown repairs using a little $25 oscilloscope (the ZEEWEII DSO154Pro) from AliExpress before. I've also used the pictorial fault guide. I shy away from using my logic probe because I don't think it gives you enough information and can be too misleading sometimes. But you've got a point.

Good morning, Bora. Glad to see you're still sticking with me. You're right, this one was expensive, but it could have been worse. I don't like to give up on a machine just because it costs too much to repair, though. If I've got the spares, I'll save it. I put the first replacement PLA in the board before I fixed those "sockets" under the RAM, while the voltage was still reading below 4.3V, so there COULD have been a short on the board that affected it. I'll never know now. I did spray deoxit into the power connector and then insert and remove the plug several times. It had no effect at all on the voltage, though, so I don't think there's a problem there. I'm still fine-tuning my diagnostic process, so I'll consider yours. Looks like you're maybe a little more cautious than I've been. And I only usually get to the dot and color clocks if I'm seeing video issues. Thanks again for watching and for your feedback. I always learn something from you.

@@YARC-1981 Of course I am sticking around. Your channel is one of my top 5 retro computer channels, always makes me happy to see a new video from you!

Thank you.

I'll try :)

I've no regrets about any of the rework I did. Those sockets were crap and the soldering on them left much to be desired. The MT RAM would eventually have caused a problem, as would the MOS logics. The only thing I regretted on this one was making the assumption that the VIC-II was working. You know what they say about when you assume.

I believe c0pperdragon and IanSB (of the RGBtoHDMI) worked extensively on that with the help of another user who was doing outside testing for them. You can follow the thread in c0pperdragon's LumaCode GitHub repository (github.com/c0pperdragon/LumaCode/issues/7), but I believe they got most, if not all, of those issues addressed, so it should handle most of those games.

@@YARC-1981 excellent!! This gives me reason to have someone redo my video mod then. I always lamented how even the RetroTink 5x pro struggled with even a composite-modded 2600.

Still don't understand how I did that.

Thank you, Dev! High praise. I'm humbled.

Yeah, I glossed over the clocks. The CIA's were otherwise 100% working and I don't think those small variances will really cause much of an issue. I had no regrets about the RAM or MOS logics. As for Mom and Dad, it's an ebb and flow thing. Some weeks are harder than others. We've been working on final arrangements for my dad so we don't have to have the burden when that time comes. Mom had a fall a couple of weeks ago and tore up her wrist pretty badly (not broken, fortunately), but she's healing up nicely from that now. I'm glad to see me back, too. I'm ever grateful for the destressing effect this hobby brings. And the community has been SO supportive. Thanks, Donald!

You're welcome. I'm assuming it was because of failing DRAM refresh, but I don't know that for 100% certain. It does seem to make sense, though.

Thanks 👍

Great eye for detail. Yep, I noticed that, too. Although both CIAs worked completely otherwise, there was a small difference between the two TOD clocks. Both are definitely getting the exact same signal driving the clocks, but they just seem to handle it slightly differently internally. I've never seen that before, but I suppose it could be normal. I don't really know for sure. Thanks for pointing it out.

Version of which?

@@YARC-1981 joust(the bird game)

@@YARC-1981 was upgraded to 64k, microdeal version I think

Oh, donkey(king) too, both played well mode 3, as did time bandit. Others looked better in bw but we never got the artifact colors in the UK...

@@YARC-1981 my father sent his world map program to hot coco and had it published! He got lots of requests from USA on if he knew how to implement the artifact colours. Great days

Gaming is "supposed" to be for kids. Kids have better imagination. As adults, we sometimes lose that. We look for precision. When I was a kid, I didn't mind the chonky block graphics and horrible RF interference I got on my Atari 2600. I could imagine myself transported into these worlds and none of that mattered. As an adult, bad picture grates on my nerves and I can't stand to play Atari's original PacMan port. So I guess it depends on the observer and just how much imagination they have left. Thanks for watching and for the insightful comment.