A couple of tips for desoldering, after sucking the solder off, wiggle each pin with some tweezers to make sure they are completely free. Another thing which can help on double sided boards (and you definitely aren't keeping the ic) is to use side cutters and cut all the legs off the ic, then desolder one pin at a time.

It's amazing how high the failure rate of the power switch is for the Commodore 64. I cleaned one the way you did with isopropyl alcohol and it worked for maybe half an hour. Then I replaced it along with a Kernal ROM and Basic ROM and everything started working. Excellent video. The person who took that Commodore apart to repair it didn't have a clue about what they were doing before you got a hold of it.

I love these detailed repair videos, great stuff! Hope to see more of this kind. I did buy that same desoldering station because of your recommendation, and it is really a great thing for the price.

Good work! Those diagnostic carts look extremely useful

Very nice save! You know, I often think I will skip a bit here and there. But I always end up watching the whole thing, hehe.. Lovely video.

Like watching a detective at work, fascinating, thank you very much!

It was a nice experience to watch your work.

Kudos for showing what can go wrong when desoldering ICs, nice job on repairing the broken traces. The RAM chips are a pain on some boards, especially the ground pin (the large copper plane draws all the heat out of the iron). I find it helps to brush on a tiny layer of flux paste across the pins before you start, although I can only hope it all gets caught in the desoldering station's filter.

Excellent video Jan, this one looked quite a challege.

I really like these repair videos. I'm thinking one day I might buy a broken breadbin C64 and then try to repair it and hopefully save some money that way. These videos of yours will greatly help with diagnosting faults. I have a C64C already, but I would like to get a breadbin because of the better SID and avoiding the VSP bug that plagues many C models, including mine, which will cause certain games to crash. Great video as usual Jan!

Jan, food for thought in the future. Two things i would suggest were a misstep. First, since you suspected the switch was bad, and the back two pins were not connected, i would not have soldered them, knowing i probably would have to unsolder them again. Secondly, simply temporarily shorting the switch pins out would have told you if the switch was the only issue.

good work as always Jan, thanks for sharing

Great video Jan. Enjoyed it a lot.

Awesome vid Jan. Thank you!

Thank you for your video. I find that pre-heating the entire PCB with a big old heatgun helps no end when desoldering chips - in other words the desoldering iron has less 'work' to do in getting those presky solder joints hot enough to melt the solder.

Congrat jan, you did again.

Good to know the 74LS257 can be bought from Digikey, and a quick search found lots of 4164 chips on eBay and other sources.

Super Video, ich hab wieder was gelernt :-)

Hi Jan, i bought a c64 250407 rev c, with a black screen issue and no led, i try'd to find the problem starting with the powerswitch, spray it in, leave it and switch now and then. Suddenly there was a start up screen 😀 and its working, at least the start screen and some small tests. Thanks for your hints. Regards Rijk

I have the same board. It's never been worked on or opened. But did notice the big caps had signs of smoking on the negative side. So I have a cap kit. Only socketed chip is the SID. I was told it worked and the caps smoked when I plugged it in.

Looked up the ASSY number for my C64 and this popped up in the results. Luckily I already know it works (seller tested and refurbished it, he even put a sticker on the cartridge port), I’m just waiting for the AV cables and PSU to get here as the seller didn’t have any of those to spare.

Bravo! Wonderful fix. My initial thought was CIA's or PLA when I saw the garbled screen, but you narrowed it down to those nasty MOS logic ICs quite quickly. Thank goodness for the Dead Test and Diag carts; they save a lot of grief. Great work -- another C64 resuscitated. I can't wait to see what your plans are for the case. Did you ever get any of the replacement case clips from @povvercrazy? Maybe I shouldn't be guessing.

Hey Jan, couldn't you test for faulty ram chips by piggy-backing them with new ones before pulling and resocketing?

Yeeees! +1 C64 back to life :)

Nice repair job! Some good diagnostics :) Reminds me I need to repair my C64C still, it has a chip which is burning up, I think it's either a RAM or Multiplexer chip, just been lazy in getting replacements and doing it lol

Just to make sure the old chips really were bad, you can use the TL-866 to test them. You can test 74 series logic chips too.

ME too, after changing fail sw, i got the screen, but can not figure out which ic fail?

Great job! As always you resurrected another 64 from death!

ok thanks, what RAM/ROM programmer are you use to test RAM and ROM chips? does your programmer test all kinds of TTL families IC chips or just a few TTL families?

Hi me c64g shows me black sreen sometimes. When i use black box with reset it work 100%. What can i check ?

Great vid jan. I would have changed the mos chips first. But you can never tell🤔🙋

Very nice video Jan. Thanks for they great videos. Though I saw you dab soldering at ~31:00. :)

Thanks for another good video, after coming across your channel a couple of weeks ago I decided to try my C64 which I brought a year ago. I bodged a cable up to my tv's start plug and switched it on and got a blank screen. Some of the chips had been socketed (the 2 CIA's the PLA and the big chip next to the PLA) so I removed the CIA's and it improved. I then put the original U2 chip in U1 and it sort of worked but the characters where changing colours. I'm now waiting for a replacement CIA chip, but if there's still a problem with the characters I'll look at the PLA which is getting hot. My case also has all the clips broken off, so I can't wait to see what your fix is, although I don't have access to a 3D printer. Also I'm going to have ago at retrobrighting this weekend as my case is very brown and it speaks of a sunny weekend here in the netherlands.

Hi, thankyou for your great videos... Can you help me where to find a new power switch? Its a commodore custom power switch? I think not... I'm having trouble looking for it on ebay or aliexpress.

Awesome video as usual! Plus, I noticed the dead test cart has the "proper" spelling of "color". LOL!! :-D

thanks for another great video. it helps me moving forward in my repair process. the mos 74ls257 were both bad in my case. Quick question: I see that you have a nice C64 saver power cable. where can I buy one of those?

Great! Why they used custom chips where 74LS exist. Strange. Where do you buy the precision sockets? The ones I have are bad quality

Nice video, now waiting for the breadbin with similar issues, wander what will it be in my case.

I have the opposite problem with the power.. I have the 5vDC but I don't have the 9vAC. i just checked the power cable and i get 10vac on pins 6/7 but when i check the inside pins 6 and 7 i only have .2vAC on pin 7. Shouldn't i have 9vAC on both 6 and 7 inside the case? And if its the switch what can i do to fix it/replace it? I have no power coming from VR1 or VR2 on the right most pin....

I have this model with a sid 6581 that gets it 12 volts but I get no sound from it what do I do?

can anyone help please, my 64 types characters by itself even with 2 known good cia chips fitted and keyboard removed

JAN BETA, How does the c64 diagnostic program know how to test each RAM chip and ROM chip, how does it test each RAM and ROM chip? the diagnostic program must have the address mapping and decoding built in?

Cool wieder einer mehr.

Cool video. In the future it will probably be possible to print IC's as long as someone has the blueprint for it.

@4:09 why are these circuit lines so loose from the board? does they still work ? is it normal ?

I gave you the thumb up but honestly this video is not your standard!! Either you are tired or not in the mood while making this video!!!!

Given that the RAM chips are no longer produced, might it be a better strategy to replace the multiplexers first when you see such memory errors? The 74257 is a very popular IC and is still in production so you can consider them "disposable", as opposed to the precious RAM chips.

I suggest soldering the switch pins, for extra mechanical strength, to reduce the chance of it breaking the joints in the other connections

22:57 - Sorry Jan, i know this is the Jan Beta from the past who did this, but i was cringing while i watched you prying up that RAM chip with such force, and then you broke the trace! So for anyone in the future watching this. You want to use the de-soldering station like Jan did, but then after that also use a hot air station to heat the pins and then remove the chip using very little force at all. From my experience, i've never been able to get the chip out with the desoldering station alone. Even the smallest amount of solder remaining in the join will hold the chip in and cause the trace to rip if you force it out.

What is the story of the photo in front of the monitor with Cannon Fodder on the screen? Apologies if this has been asked before.

Hello Jan Beta my commodore 64 also has a black screen video chips are good but the rams bad when I touch it it's like super hot to the touch is it easy to solider on sockets then put the new chips in or not? also Does it matter which chips I get or not because there's many different ram chips for the Commodore 64? and Due to the fact my C64 is brand new in the box in mint condition by me replacing the chips would that affect it's value in the future or not in terms of originality?

Desoldering can go wrong quickly with a lot of heat and impatience . I certainly will take my time using my duratool desoldering iron as recently I tried taking off a 44 pin header which was a nightmare as the through holes were tiny as hell and the gun kept clogging up with pins . Madness .

why does it need the 10v ac? is it 50hz?

Just curious, what is the problem with the donor board?

Nice job. Fear the traces on the old boards sometimes they require more TLC than your significant other besides computers are your best friend when they act up they can be reset unlike ones significant other which do not come with a reset button (Ahem). Don't be too hard on MOS Chips hey many fail but many are 30 yrs and still functional. The board I am working on right now is also a 250407 its a waiting game for me that is waiting for parts to arrive and then I need to wait for when I am off from work.

that beeping sound of fastforwarded desoldering sounds so funny

Nice repair and all, but where can I get myself a sweet LIPS brand monitor like yours Jan Beta? :)

Is that U8 chip with the "beta" logo (at 23:34) the original one that came with the C64? That chip is produced at IPRS Baneasa in Bucharest, Romania :) I'm proud to see it in a C64!

What a most reliable vic-II? 6557/8562/8564 for ntsc . 6569/8565/8566 for pal. I want buy one pal and one ntsc

Dieses Auslaufmodell hat doch seine Popularität nur dadurch zu verdanken weil es mehr rem hat und Commodore das Ding verschenkt hat wenn man mit einem günstigeren Heimcomputer um die Ecke kam. Der C 16 ist aber Leistungsfähiger.

It's a shame that so many of the parts that these old computers used are getting harder and harder to come by. Good thing we have modern alternatives to these old systems like the Raspberry Pi (via emulation). I think there's even an FPGA-based system that can emulate just about anything you can think of, not with software but with actual programmable hardware. Still nice to run stuff on an original system, though. I think I still have my breadbox 64 around here somewhere...

why you cover the brand of the screen?

hey ive got the same postcard from amigastore :)

excellent fix but heat not more than 3 seconds, use flux

what is the chance that three independent components fail?????

We should go a little easier on Commodore (and other 'golden age' computer manufacturers) for using chips that can go bad: They were not thinking that people might be using their systems 30 years later! To be honest, I'd say that MOST of those old systems - if they were at least relatively well-cared for - are still working not too bad. My 1987 Amiga still works just fine, for example...

YEY !!! DM KLOPAPIER !!!!!

I just killed a C64. :( It did't really work before, but now it is definitly dead. It didn't take any inputs or have sound (tried that with a cardridge game). I took the SID chip out of the socket, cleaned all of the contacts and put it back in. I pluged it in but only partly assembled. First it worked, I had sound again and I was really happy. But then I wanted to turn it back off to put it back together, but there were sparks coming from the board when I tried to plug the power cable out. Then I realized that the cardboard that originally was in the C64 I put the board on has a piece of metal on it, where it was attached. And this piece of shit touched the board when I tried to turn it off. First it was a wierd pattern on the screen. But after I finally got it disconnected from the power, and then plugged it back again it only shows a white line on a black screen. But the worst thing is, that I probably killed a working VIC and a working SID chip. Now I have to write it somewhere because I really still can't belive that I really did something that stupid. 😢😭😭😭😭😭 Is there any chance the that at least the SID chip still works?

I liked the 250425 and is more reliable than the 250407.

When I remove chips, I tend to first clip the pins to protect the board.

Jan: I've taken a look and I think there is a good chance it might be this thing. Me: Hmm, yes, very good. *Still ⅔ of the video left* Me: No you idiot, of course it isn't that.

im gona admit someting c 64 was better than spectrum.

Retrotech is selling proper new and compatible power switches. www.demand.nu/retrotech/r8017l-r21.html Goldplated sockets make the chip pins oxidize faster, ideally they should be the same material.

You are manhandling that board into oblivion... bashing and banging, droping the fluke on it all the time... you are gonna have a lot more to repair with that kind of abuse. I had a faulty power switch on my 64 too, the contacts were totally black inside. It's pretty easy to disassemble, clean and reassemble the switch.

LOL @ severely dead. my C64C was severely dead as well. BSOD --> Black Screen of Death due to dead CIAs

Circuit board butcher......

why there is a toilet paper on the bench? R u goin to sh*t on the C64? lol