Great work bud 👍. We're only human mistakes happen. I have myself once mixed up the pla and sid, and once I had the basic and character roms switched when testing.. dead test no problem... but no basic screen or diag... took me a couple hours to find it and be like duh. ❤ man:)
Yeah. i know I can't be perfect. Just makes me feel so foolish when I do something like that. Fortunately, this mistake didn't cause any further damage. I've done that before and that really hurts. This one only cost me a ton of time. Thanks for watching and for the encouragement.
I know a zif board is handy, and low hanging fruit is tempting, but for understanding how to spot a bad cpu or cia or pla using your oscilloscope is much more useful than a quick "this chip is bad cause it doesn't work in my other machine" video. I do enjoy your effort and the continued homage to Adrian Black by using his signature sound test.
Yes, I tested the four socketed chips in the ZIF machine, but that was more because I actually suspected they were good. Testing them that way is quick and reliable. Testing using an oscilloscope on a broken board usually won't tell you if a chip works because if there are faults elsewhere, those can affect any results you get on the chip you're trying to verify. If you'll recall, I did spot the PLA problem by testing the outputs with the oscilloscope. The ROM selects weren't behaving correctly. I only verified my suspicions using the ZIF board. I suspected the SID because it was particularly warm while not actually producing sound or being used for paddle input. Then, in the four-hour section I skipped, I had the oscilloscope all over the board tracking down address bits 8 and 9, which were stuck high-ish. I only desoldered a chip and tested it outside the board if it was giving me indications on the scope that it might be bad. As for the Donkey Kong Arcade theme, part of that is homage to Adrian, but most of it is because that's the song I'm most familiar with. I didn't grow up with a C64, so I'm not familiar with a lot of game themes or demo music that's out there. I can hear subtle problems in the DKA theme, whereas I wouldn't necessarily hear them in other music. Thanks for watching and for the input. I'll keep it in mind as I try to improve my process.
Thanks for the video and don't worry: as we say here, the one who doesn't make mistakes is the one that does nothing. So, in the end it was a bad PLA and SID? I find your way of soldering/desoldering pins interesting, not going one by one in line, but going zig zag
Thanks for watching and for the absolution 😂. Yes, the PLA and the SID were the only two faults in the end. I got in the habit of soldering that way to avoid heat build-up in a certain area of a chip. If you do it on the diagonals, you give each area more time to cool between heating adjacent pins. I can't remember if someone taught me that or if I came up with it on my own, so I won't take full credit. I also don't know if it really matters at all. Just a little quirk I have.
It's good to see you "Finally" solved it and the C64 is singing & dancing again. But did you actually solve the Low +5Volt rail ? I'm seeing lately more of this board, with that very issue (among other issues). My solution to this so far has been to 'Shotgun' all the 10uf 25V Electro Caps (yes even the pair inside the Video / clock metal shield - where the supply is derived from the 9v AC). Why? Well not only to restore the +5V rail but also before removing these caps I'm seeing varying levels of tarnish/corrosion on the Solder joints below the caps (and nearby components) to corrosion on/under the soldermask & PCB surrounding the electrolytic caps. Now I'm not PRO , let's Shotgun everything (except for known boards with leaking Caps ... thanks Mac & Amiga) and then see what it's doing (that way of thinking if you are not careful will end up causing more issues (broken tracks / shorts , wrong value/ reverse polarity, etc.) and chasing your tail). Now previously I've heard people say Electrolytic Caps in a C64 won't stop your computer from booting up. Well I've seen over the years multiple Caps preventing the reset circuit from working and some caps in the RF Modulator preventing video out, But now am also seeing on the 250407 boards leaking caps. So be warned, and take appropriate action when needed before your C64 gets damaged.
You're right, I missed out showing the power rail after I fixed my little mistake. Yes, it did clear the problem. As for the caps, I always look for visibly leaking electrolytics, but I've never actually found any on a C64. They can still be out of spec without leaking, though. Bad caps around the 555 timer could definitely affect the reset circuit and bad caps in the RF modulator could affect video quality. I don't usually recap a C64 unless I'm seeing symptoms that suggest a problem. Thank you for watching and for the information. As I said, I really appreciate hearing from the community and all the info you all provide. Cheers!
I am as careless as you are, and from one to another, here is my tip for not putting the ICs in wrong sockets; Before you start pulling them off, write on them what they are with that white marker. Very easy to confuse ICs with faded markings but believe me you won't put an IC marked with big white letters as CIA in a CPU socket.
Thanks, Bora. I guess I just figure I will recognize them by the part number. That doesn't work if you don't pay attention while you're doing it, though. Maybe I should start marking them. That white "marker", though, is a paint pen and a little harder to remove afterwards. I'll look for something else to mark them with.
Great work bud 👍. We're only human mistakes happen. I have myself once mixed up the pla and sid, and once I had the basic and character roms switched when testing.. dead test no problem... but no basic screen or diag... took me a couple hours to find it and be like duh. ❤ man:)
Yeah. i know I can't be perfect. Just makes me feel so foolish when I do something like that. Fortunately, this mistake didn't cause any further damage. I've done that before and that really hurts. This one only cost me a ton of time. Thanks for watching and for the encouragement.
I know a zif board is handy, and low hanging fruit is tempting, but for understanding how to spot a bad cpu or cia or pla using your oscilloscope is much more useful than a quick "this chip is bad cause it doesn't work in my other machine" video. I do enjoy your effort and the continued homage to Adrian Black by using his signature sound test.
Yes, I tested the four socketed chips in the ZIF machine, but that was more because I actually suspected they were good. Testing them that way is quick and reliable. Testing using an oscilloscope on a broken board usually won't tell you if a chip works because if there are faults elsewhere, those can affect any results you get on the chip you're trying to verify. If you'll recall, I did spot the PLA problem by testing the outputs with the oscilloscope. The ROM selects weren't behaving correctly. I only verified my suspicions using the ZIF board. I suspected the SID because it was particularly warm while not actually producing sound or being used for paddle input. Then, in the four-hour section I skipped, I had the oscilloscope all over the board tracking down address bits 8 and 9, which were stuck high-ish. I only desoldered a chip and tested it outside the board if it was giving me indications on the scope that it might be bad.
As for the Donkey Kong Arcade theme, part of that is homage to Adrian, but most of it is because that's the song I'm most familiar with. I didn't grow up with a C64, so I'm not familiar with a lot of game themes or demo music that's out there. I can hear subtle problems in the DKA theme, whereas I wouldn't necessarily hear them in other music.
Thanks for watching and for the input. I'll keep it in mind as I try to improve my process.
Great job fixing these C64s!
Thank you. I appreciate that. And thanks for watching and commenting!
Occam’s razor. Sometimes the best is stop, and come back the next morning to take a look at it again….
Or just pay closer attention the first time. Thanks!
Thanks for the video and don't worry: as we say here, the one who doesn't make mistakes is the one that does nothing. So, in the end it was a bad PLA and SID? I find your way of soldering/desoldering pins interesting, not going one by one in line, but going zig zag
Thanks for watching and for the absolution 😂. Yes, the PLA and the SID were the only two faults in the end. I got in the habit of soldering that way to avoid heat build-up in a certain area of a chip. If you do it on the diagonals, you give each area more time to cool between heating adjacent pins. I can't remember if someone taught me that or if I came up with it on my own, so I won't take full credit. I also don't know if it really matters at all. Just a little quirk I have.
It's good to see you "Finally" solved it and the C64 is singing & dancing again. But did you actually solve the Low +5Volt rail ? I'm seeing lately more of this board, with that very issue (among other issues). My solution to this so far has been to 'Shotgun' all the 10uf 25V Electro Caps (yes even the pair inside the Video / clock metal shield - where the supply is derived from the 9v AC). Why? Well not only to restore the +5V rail but also before removing these caps I'm seeing varying levels of tarnish/corrosion on the Solder joints below the caps (and nearby components) to corrosion on/under the soldermask & PCB surrounding the electrolytic caps.
Now I'm not PRO , let's Shotgun everything (except for known boards with leaking Caps ... thanks Mac & Amiga) and then see what it's doing (that way of thinking if you are not careful will end up causing more issues (broken tracks / shorts , wrong value/ reverse polarity, etc.) and chasing your tail). Now previously I've heard people say Electrolytic Caps in a C64 won't stop your computer from booting up. Well I've seen over the years multiple Caps preventing the reset circuit from working and some caps in the RF Modulator preventing video out, But now am also seeing on the 250407 boards leaking caps. So be warned, and take appropriate action when needed before your C64 gets damaged.
You're right, I missed out showing the power rail after I fixed my little mistake. Yes, it did clear the problem. As for the caps, I always look for visibly leaking electrolytics, but I've never actually found any on a C64. They can still be out of spec without leaking, though. Bad caps around the 555 timer could definitely affect the reset circuit and bad caps in the RF modulator could affect video quality. I don't usually recap a C64 unless I'm seeing symptoms that suggest a problem. Thank you for watching and for the information. As I said, I really appreciate hearing from the community and all the info you all provide. Cheers!
I am as careless as you are, and from one to another, here is my tip for not putting the ICs in wrong sockets; Before you start pulling them off, write on them what they are with that white marker. Very easy to confuse ICs with faded markings but believe me you won't put an IC marked with big white letters as CIA in a CPU socket.
Thanks, Bora. I guess I just figure I will recognize them by the part number. That doesn't work if you don't pay attention while you're doing it, though. Maybe I should start marking them. That white "marker", though, is a paint pen and a little harder to remove afterwards. I'll look for something else to mark them with.
@@YARC-1981 The white marker I use, although it says "permanent" on it, is easily wiped off completely with a tissue soaked in IPA.
Errare hunanum est, bro. Errare humanum est.
The rest of that saying is "perseverare autem diabolicum" or "but to persist (in error) is diabolical" I'm diabolical. Thanks for watching!