A classic Commodore 64 repair!

Let’s dive back into the bin of broken dreams and see if we can save another C64!
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[@PresJPolk]

I'm glad you're willing to make videos like this. A common trap I see a lot of channels like yours fall into, is that you chase an ever-increasing level of production quality, to the point where it actually harms your ability to put out videos at all. Lots of channels exist about old computers. The unique quality about your channel is you. Be yourself.

[@retrobitstv]

This is very insightful and you've really hit the nail on the head. From the beginning I've been chasing production quality and a lot of time went into videos that ended up under-performing. In order to stave off potential burnout, in 2024 I'm committing to trying out new styles, hosting more livestreams, and not chasing the algorithm by only making videos of stuff that I want to see. Thank you for the feedback and encouragement 🙏

[@jandjrandr]

I have to agree. It is important not to get "stuck in the weeds" as they say trying for perfection. You want to provide good content of course, but the most important aspect is just be you. You will get the right group of people wanting to watch your content then.

[@MitzaMaxwell]

I've been told that the reason Commodore used sockets in a random order is because when some components were out of stock they used a socket and fitted the component later when it was back in stock.

[@retrobitstv]

I hadn't heard that before but it makes perfect sense!

[@rdh2059]

Like many others, I went through a phase where I sort of became addicted to repairing Commodore C64s. Although I've had some 6510's fail, by a large margin, the issue is typically the PLA, MOS made logic chips or M/T RAM. Jan Beta sort of created the c64 term "future-proofing". It would be in that computer's best interests if all MOS logic chips (I saw 1 for sure) were removed. The other chip that fails quite often is unfortunately the precious SID. Your diagnosis approach is spot on and your soldering technique is very good. Good video and congrats on the repair!

[@JanBeta]

Very well done and I actually like these kinds of less planned-through videos a lot! Unfortunately the 6510s fail quite frequently in my experience. :/ One little thing I noticed: while testing the voltages, you should also test the 5V rail coming directly from the power supply (for example on the user port), as that rail powers most of the ICs in these older breadbins (that's also why a bad power supply often kills multiple chips at once). The voltage regulators are used as a cleaner supply for the VIC-II and the SID to minimize noise.

[@retrobitstv]

Thank you for the feedback! I haven't yet had a 6510 fail in one of my own machines, but I've only worked on a small number of 64s up till now. Good to know; I didn't realize that about the regulators vs the PSU. I guess I'm going to have to study the schematics a bit more and brush up on the power supply side of things for next time!

[@killr0y]

"This case has been opened violently before" 🤣🤣 Thanks for showing us Yeti Mountain, looks amazing!

[@crashoverride328]

Any time you are trying to desolder a large thermal mass low melt solder will b e your very good friend. The resultant alloy's low melting point simplifies the removal process a LOT.

[@00Skyfox]

If the 6510 can be replaced with a modified modern 6502, you should do a video walking through all the steps involved in that. It would be very informative and interesting.

[@PlumGurly]

Yes, even if you only get 95% compatibility. It is a board that uses the 65C02 (or an older, original 6502) and intercepts the first 2 addresses on the bus. It's not quite how the 6510 did it, but it works.

[@coryengel]

Ditto. Love the unscripted repairs.

[@marcvincent1691]

That was great ! Debugging tutorial videos are very helpful, thanks !

[@gosammy1971]

Nice, i need my daily episode of a fixed c64

[@brezel53]

Fantastic, more please!❤

[@networkg]

An excellent video. A straight forward step by step approach to solving a problem. Your video is now bookmarked as a favorite. Something I am still hoping to find is a good video that shows every test point on a working C64 and the expected result (Oscilloscope screen, multimeter reading etc.)

[@retrobitstv]

That would be a very useful resource. I'm not sure I've got the knowledge or equipment to gather all the correct information but certainly something I'll think about!

[@BerniesBastelBude]

impressive work!

[@michaelstoliker971]

What's a retro show without at least one dead C64? Just my luck I bought 2 and they both work!

[@panopolis8051]

yeah, it's always a bit disappointing when you buy an "untested" old computer and it just works, half the fun is fixing them!

[@retrobitstv]

...for the moment, at least. Give it some time 🤣

[@kirgahn]

Not to turn down your high quality production videos, but love this format. Your delivery is really smooth, which makes it really easy to follow and enjoy the video.

[@retrobitstv]

Thank you for the feedback, I guess I will have to consider making more like this in the future :)

[@peteregan9750]

the informal style for repairs is great - nice to change things up a bit

[@8antipode9]

I repair old machines myself (although not on YT) and I do enjoy watching others go through their troubleshooting process. Thanks!

[@retrobitstv]

I'm still consider myself a novice at repairing these machines but I'm learning a bit more with each effort :)

[@8antipode9]

@@retrobitstv Yeah I consider myself a novice too, but I've definitely learned not to give up. At worst, put it aside and come back another time.

[@mikegage3326]

Nice repair video. Thanks for explaining the logic you used to troubleshoot the C64.

[@Breakfast_of_Champions]

It's a good introduction the general electronics fixing process on these simple machines.

[@SidebandSamurai]

Love the format. Keep it up

[@csico81]

I really liked this video! Please do more like this.. Keep up the good work :) Greetings from Switzerland ;)

[@lolocloud9611]

pretty cool stuff

[@SpaceAce57201]

First video I have watched of yours. Love the format! ✌️

[@mogwaay]

Hey Mat I couldn't make the live stream, which was a shame as I thought it sounded fun. I liked the casual repair here too, well done getting it working.

[@TheStuffMade]

Always good to see another breadbox brought back to life 👍. Spending $30+ on a new CPU is probably not worth it at this time, but who knows maybe someone will come up with a cheaper clock perfect replacement in the near future. I recently had to bite the bullet and spend $35 on a new VIC chip for my c128, I think it was worth it because it's back to fully working, but it's quite a lot of money.

[@tommyovesen]

Great video. Always nice to see a dead C64 come back to life!

[@ASMRPoohbear]

Love the repair video style. Music could be removed though

[@StrapMerf]

LM556 is a timer chip. it's a dual LM 555, used for clock and for reset line hold down(timed) I dont know what that particular 556 is used for though

[@SeanChYT]

Commodore 64 machines usually only have one of those.

[@KlingonCaptain]

Why has it been impossible for me, over the years, to find a Commodore 64 in the wild when people on KZbin literally bins filled with them?

[@fu1r4]

5:25 You need a bigger tip. That small tip doesn't work!

[@gawkersdeathrattle1759]

@retrobits I'd love to do this, but I have no idea where one acquires a plethora of dead machinery upon which to practice and learn. In the words of a certain version of The Joker -- "Where does he get his WONDERFUL toys?"

[@killr0y]

They were collected/purchased over the decades but with only basic troubleshooting tools didn't get very far. Best bet is to check local thrift stores, e-waste recyclers, Facebook marketplace, eBay, etc.

[@retrobitstv]

I see a lot of posts on Reddit where people have dug out an old C64 or recently bought one, it's dead, and they don't know how to fix it. You might try offering to help in one of the Commodore or C64 subs perhaps?

[@gawkersdeathrattle1759]

@@retrobitstv Heh, I don't know if I could "offer help" so much as offer to educationally destroy everything until I learn how I can be helpful. :D Don't get me wrong, I'm familiar around electronics, but we're talking in some cases machines approaching 50 years old and have never been in better state than 'tempermental'. I don't know if I could bill myself as a positive force until I've dug into a few repairs.

[@jeffstack4217]

in regards to the RF shield, I just generally 'push' on it with the tip of the soldering iron as the solder melts, it's a one step process. There's a finesse or learning curve to it, but once you get it, it's easy peasy. However, that's on units where that is to be salvaged, otherwise, just cut them off. ;)

[@retrobitstv]

I thought about trying that but I wasn't sure if it would damage the finish on the tip or not!

[@grailknightofenoch1263]

love your vids

[@Charleshawn66]

TY for the years of GREAT Commodore content! Where did you buy it that device that turns the power plug 90 degrees to the rear or did you 3D print its case and make it. I bought a new 3D printer (Anycubic Kobra 2 Pro) and really need to start using it! lol

[@retrobitstv]

There are plans on the net for how to build your own, but I just bought this particular part: www.commodore-4ever.com/product-page/64-to-64-90-degree-adapter-commodore4ever

[@terosaarela4555]

Very nice and laid back video to follow! Have you looked into the J-CPU?

[@retrobitstv]

I have now! Thanks for bringing that to my attention :)

[@stevethepocket]

Was the sound cutting out during the diagnostic test something that happened with the recording? You didn't comment on it when it happened.

[@retrobitstv]

I was listening to the C64 audio at low volume through the laptop's built in speaker during the stream so I didn't hear the problem at the time. It does sound like an issue with the capture/encoding though - the glitch in question occurs during the volume register bug 'pop', but all the other pops sounded normal during the diag test and the SID music and game sounds all were fine too. I may go back and test the system out again later but it's already packed away for now.

[@tenminutetokyo2643]

Jam in new inductors. New modern ones are tiny.

[@Breakfast_of_Champions]

Come on I've watched the whole stream and now you want me to watch and like this video too!😀

[@retrobitstv]

There are still more broken machines in the bin 🤣

[@MikesArcadeMonitorRepair]

Dang. I was sure it was a PLA given that it’s almost always the PLA or one of the MOS branded chips (if they are present) with a black screen. Sucks that’s it’s a CPU.

[@corygraves2402]

I opened up a commodore 64 bread bin and saw a ceramic gold 6510 and was wondering if anybody else has seen one

[@pwissink1]

That power connector looks great. Where did you buy it?

[@retrobitstv]

I purchased it a few months ago from this vendor: www.commodore-4ever.com/product-page/64-to-64-90-degree-adapter-commodore4ever

[@bobsbarnworkshop]

Hi Matt! How can I send you a couple “goodies”? Do you have a PO box?

[@retrobitstv]

Hi Bob, please feel free to reach out to me at [e-mail] thanks!

[@WizardNate]

6:12 when you say to “cut them off”…how would you go about doing that?

[@WizardNate]

For those curious, I ended up using a small pair of End Cutting Pliers to gently pry the RF shield away from the board before applying more pressure to break the solder. Worked really well - didn’t need to heat up the solder at all and easily removed the shield in just a few minutes.

[@kevinklocke7796]

When you have no video, will you see the white line on a commodore monitor?

[@retrobitstv]

It really depends on the monitor and the failure condition of the computer itself. If you can shrink the horizontal size enough or you have an underscan button on your display you should see the white line but on some monitors and TVs without the H-Size adjustment you won't. If the VIC-II isn't getting a clock signal and power and isn't generating a video signal, you won't see any line at all.

[@w1katari]

i see many xf551.. its for sale one piece?

[@tetsujin_144]

Machine seems to be a dorito or two short

[@retrobitstv]

Still neato though :P

[@dougjohnson4266]

.

[@retrobitstv]

Thank you for your support!

[@teejmiller]

Clearly these machines came from someone mining bitcoin with the dead CPUs.

[@retrobitstv]

You jest but... github.com/ytmytm/c64-bitcoin-miner

[@ivang1014]

*Promo SM* 😈