I'm the owner of this C64 and I just want to say thank you to Mark for taking up the challenge and doing an amazing job. Definitely needs more subscribers, very underrated channel!
When you first proposed running without both CIAs, I immediately thought 'how is video bank switching going to work?' Then I was yelling at my screen the entire time you were troubleshooting that floating address line. 😆
Long time no see! Thank you for the retro content and its Commodore so that a bonus! That is a very rough looking C64! I LOVE that power brick tester you made! Is there a story why the Commodore 64 badge is upside down on your Zif C64? Beer O'clock!!! Hank is a big cat! lol
Good to see you Charles. The ZIF machine was missing a badge so I salvaged a broken one from another machine. It's upside down so I can easily tell it apart from the others
Your cat is the same color as a lot of old computer cases. I'll bet he could make like E.T. and sit on your shelf between some Commodores and blend in.
I really enjoyed that one, Mark. I've never had one with that clock problem, so I learned something new. It surprised me that the 82S100 was shot. Those are usually so reliable. No big surprise on the rest, though. I've had some bad luck with 2114's, and the ROM and CIA failing are almost as cliche as a bad MOS PLA. Great work and fun video. Cheers!
On my C64, the two caps (C108/C107) were leaked, too, and it also damaged one half of U31, resulting in wrong clocks - still producing output, but at 1/3 frequency.
Excellent work! And great video. Very smart with using the kawari to check. . I would have never thought of that:) also I have a couple c64s that show the blue when using the SD card modulator... the kernal rom rev 2 not 3 ... that's why... always bothered me, now I know. Thanks bud, and cheers
Today I learned, that this channel is my third known Australian channel. The other two are Sticky (I love sweets) and CEE Cutting Edge Engineering (hello Kurtis). 😊 Greetings from good old Germany. 😃
40:35 - wow! I’m genuinely confused, I’d always thought the RF modulator must be just for that antenna output that I never use. How does the RF modulator affect the video out from the AV DIN jack? Ok, I should look at a schematic, but that won’t tell me how your replacement is making such an improvement - great result, well done - I’d better start fixing those video problems in my own C64s. Thanks for another interesting video. I always find it surprising to have so many different faults at once. Sometimes I wonder if a machine has been used as a parts donor many years ago, and all the bad chips have ended up in it (at least the socketed ones)
The RF modulator also includes components to amplify the luma and chroma outputs from the VIC-II and mixing those signals for the composite output. These are then fed back out of the RF modulator to the AV DIN. The original RF modulator also applies some filtering, probably to conform to some FCC regulations. Problem is it does a very poor job with all this, so replacing it with a new circuit can improve the video output
I can hear the sarcasm dripping off that, but it truly IS surprising to find a bad 82S100 PLA. Sure, the MOS copies were crap, but the Signetics chips and the later Phillips PLS100 ones were very reliable.
Yet again an very interesting video, much appreciated. I recently came across an strange kernal chip in an c64. I have tried it on several different boards and with the diagnostic cart it shows "bad" every single time. It seems to be working with an normal bluescreen. Can you think of an good way how to test it out in order to see if that chip is indeed an faulty one?
You should read out the ROM with a ROM tester and than compare it to a known good ROM. There's a good ROM tester shown at the channel of Adrian's Digital Basement. When you can get the same one, there should be no further issues.
@@Dirk-Ulowetz Many thanks At the time i was making the question i was still watching the video so thanks to @TheRetroChannel i might also have one of the rev 2 kernal chips.
I don't think i've ever seen the diagnostic cart report "bad" for the ROMs. Usually if it doesn't recognise the Kernal it will report "unknown". If you can run the diagnostic then the Kernal must be working, what does it show without the diagnostic cart? Does it look like the regular boot screen?
@@TheRetroChannel Yes it shows the normal blue screen every single time. I have tested it on a few different motherboards (250407 and 250425) with the same result. If i remember it correctly when i tested it for the very first time the diagnostic test did pass.
I'm the owner of this C64 and I just want to say thank you to Mark for taking up the challenge and doing an amazing job. Definitely needs more subscribers, very underrated channel!
Your repair videos are always great and a good resource for broken c64s. Keep up the good work.
Thank you! Much appreciated
Jaycar sell DioxiT but its very expensive. $36 for tiny little bottle. Actually you get 2 bottles, DeoxiT and Gold Rejuvenate.
Should the cat not wearing an anti static paw strap ??😂
When you first proposed running without both CIAs, I immediately thought 'how is video bank switching going to work?' Then I was yelling at my screen the entire time you were troubleshooting that floating address line. 😆
just bought 2 c64s both needed PLAs..one Died after I accidentally left it on for 24 hours.
HELLO HANK 😻😻😻😻
Long time no see! Thank you for the retro content and its Commodore so that a bonus! That is a very rough looking C64! I LOVE that power brick tester you made! Is there a story why the Commodore 64 badge is upside down on your Zif C64? Beer O'clock!!! Hank is a big cat! lol
Good to see you Charles. The ZIF machine was missing a badge so I salvaged a broken one from another machine. It's upside down so I can easily tell it apart from the others
Your cat is the same color as a lot of old computer cases. I'll bet he could make like E.T. and sit on your shelf between some Commodores and blend in.
With a cat around you always know the date as they show you!
Watch till the end or you will miss the "bird."
Enjoyed the video! Good job.
Have you ever actually seen an overvolting PSU? I suspect the risk has been hyped to unrealistic levels.
I don't think I have. I've certainly come across some that didn't output anything but perhaps it's more of an issue with the North American PSUs
kitty, kitty. I got a Tux.
Came from the repair, stayed for the kitty
I really enjoyed that one, Mark. I've never had one with that clock problem, so I learned something new. It surprised me that the 82S100 was shot. Those are usually so reliable. No big surprise on the rest, though. I've had some bad luck with 2114's, and the ROM and CIA failing are almost as cliche as a bad MOS PLA. Great work and fun video. Cheers!
🍪🎂 It's ma birthday. Something to watch later.
🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎂🎂🎂🎂🎂🎂🎂🎂🎂🎂🎂🎂🎂🎂🎂🎂
@@TheRetroChannel Well that was quite the interesting ride wasn't it. After all of that I think I can share another one of these with you 🍪
On my C64, the two caps (C108/C107) were leaked, too, and it also damaged one half of U31, resulting in wrong clocks - still producing output, but at 1/3 frequency.
Excellent work! And great video. Very smart with using the kawari to check. . I would have never thought of that:) also I have a couple c64s that show the blue when using the SD card modulator... the kernal rom rev 2 not 3 ... that's why... always bothered me, now I know. Thanks bud, and cheers
Top bro
C64 with 'melt' marks from cables being wrapped around them to tight for years on end, definantly seen a few in that condition
Interesting video, as always. Is Hank going to be a regular participant, or just make guest appearances?
He might, but he is a cat so according to him I'm showing up in his video
@@TheRetroChannel 😀
I've had a C64 with virtually the same combination of bad parts; the PLA, one of the (MT) RAM chips and the 8701.
Today I learned, that this channel is my third known Australian channel. The other two are Sticky (I love sweets) and CEE Cutting Edge Engineering (hello Kurtis). 😊
Greetings from good old Germany. 😃
I found a good way to clean corroded pads is with a fiberglass scratch brush pen, might want to check that out!
Cool video, even better after a Saturday lunch. Thanks for it and keep up the good work.
I'd love to get a bread bin again. Still amazing how good the C46 is.
Always great videos! Thanks for sharing
40:35 - wow! I’m genuinely confused, I’d always thought the RF modulator must be just for that antenna output that I never use. How does the RF modulator affect the video out from the AV DIN jack? Ok, I should look at a schematic, but that won’t tell me how your replacement is making such an improvement - great result, well done - I’d better start fixing those video problems in my own C64s.
Thanks for another interesting video. I always find it surprising to have so many different faults at once. Sometimes I wonder if a machine has been used as a parts donor many years ago, and all the bad chips have ended up in it (at least the socketed ones)
The RF modulator also includes components to amplify the luma and chroma outputs from the VIC-II and mixing those signals for the composite output. These are then fed back out of the RF modulator to the AV DIN. The original RF modulator also applies some filtering, probably to conform to some FCC regulations. Problem is it does a very poor job with all this, so replacing it with a new circuit can improve the video output
Great work. Bonus points for Hank.
Great Video! -Mark.
What a nice cat you have.
A failed PLA? I'm shocked.
I can hear the sarcasm dripping off that, but it truly IS surprising to find a bad 82S100 PLA. Sure, the MOS copies were crap, but the Signetics chips and the later Phillips PLS100 ones were very reliable.
The Australian Adrian Black 😉
It farkin' werks!
Yet again an very interesting video, much appreciated. I recently came across an strange kernal chip in an c64. I have tried it on several different boards and with the diagnostic cart it shows "bad" every single time. It seems to be working with an normal bluescreen. Can you think of an good way how to test it out in order to see if that chip is indeed an faulty one?
You should read out the ROM with a ROM tester and than compare it to a known good ROM.
There's a good ROM tester shown at the channel of Adrian's Digital Basement. When you can get the same one, there should be no further issues.
@@Dirk-Ulowetz Many thanks At the time i was making the question i was still watching the video so thanks to @TheRetroChannel i might also have one of the rev 2 kernal chips.
I don't think i've ever seen the diagnostic cart report "bad" for the ROMs. Usually if it doesn't recognise the Kernal it will report "unknown". If you can run the diagnostic then the Kernal must be working, what does it show without the diagnostic cart? Does it look like the regular boot screen?
@@TheRetroChannel Yes it shows the normal blue screen every single time. I have tested it on a few different motherboards (250407 and 250425) with the same result. If i remember it correctly when i tested it for the very first time the diagnostic test did pass.
@TheRetroChannel Oh i forgot to ask if you could enlighten me which kernal is v2 and which one is v3? What are the differences?
Nice and interesting video