Bought a whole lot of CC II/LC520 and LC475/575 boards from a forum member and been busy repairing them last weekend. Figured I might make a thread here and log my findings.
Entire board is covered in electrolyte, especially the section near battery so I guess it's been battery bombed. After washing it I can see some corroded traces near CPU. All legs on PrimeTime/Memcjr chips appear tarnished and are covered under a layer of brown residue. Green crystals also form on top of some vias so they might be damaged as well.. Need to check and repair traces later.
This board is in better condition than the first one, although all caps appear to have leaked but doesn't cause much damage. Washed the board and did a full recap, also pulled DFAC-II to clean pads underneath. Just a side note, if your CC/CC II/LC475/575 board doesn't have sound after recap, or simply doesn't power on at all, pull DFAC-II and inspect solder pads underneath. If you keep using your mac like this, there's a chance you will fry the sound chip, I learned this the hard way.
After cleaning all electrolyte residue and a recap, the sound is finally working.
Probably the best looking board in the entire lot. Interestingly, all caps on this board didn't leak and cap legs are still shiny. Not sure the manufacturer of these caps but at least they are not from chemicon. Did a full recap anyway and powered it on, chimes but screen flashes on and off. Tried a good pair of VRAM from my LC475, same issue. On closer inspection, the Antelope RAMDAC chip has some solder flux around it and appears someone have already work on it.
Pulled an Antelope chip from another scrap 575 board and replaced it, that seems to have solved the issue. No more flickers and original vrams are also working fine.
Unfortunately my luck starts to run out with these CC II boards. 2 brown boards are clearly battery bombed and I didn't even bother to recap them. Only 2 out of the rest 4 logic boards worked after a full recap and DFAC-II clean up. The rest 2 respond to power on button on keyboard but don't chime, screen stays black. Also noticed the 68030 CPU on these 2 boards are running too hot, I can't leave my finger on there for more than a few seconds, which doesn't seem normal. Since we don't have schematic for CC II, they will be a bit harder to diagnose, but I'll keep working on them and see what I can come up with.
LC575 - 1:
Entire board is covered in electrolyte, especially the section near battery so I guess it's been battery bombed. After washing it I can see some corroded traces near CPU. All legs on PrimeTime/Memcjr chips appear tarnished and are covered under a layer of brown residue. Green crystals also form on top of some vias so they might be damaged as well.. Need to check and repair traces later.
LC575 - 2:
This board is in better condition than the first one, although all caps appear to have leaked but doesn't cause much damage. Washed the board and did a full recap, also pulled DFAC-II to clean pads underneath. Just a side note, if your CC/CC II/LC475/575 board doesn't have sound after recap, or simply doesn't power on at all, pull DFAC-II and inspect solder pads underneath. If you keep using your mac like this, there's a chance you will fry the sound chip, I learned this the hard way.
After cleaning all electrolyte residue and a recap, the sound is finally working.
LC575 - 3:
Probably the best looking board in the entire lot. Interestingly, all caps on this board didn't leak and cap legs are still shiny. Not sure the manufacturer of these caps but at least they are not from chemicon. Did a full recap anyway and powered it on, chimes but screen flashes on and off. Tried a good pair of VRAM from my LC475, same issue. On closer inspection, the Antelope RAMDAC chip has some solder flux around it and appears someone have already work on it.
Pulled an Antelope chip from another scrap 575 board and replaced it, that seems to have solved the issue. No more flickers and original vrams are also working fine.
CC II:
Unfortunately my luck starts to run out with these CC II boards. 2 brown boards are clearly battery bombed and I didn't even bother to recap them. Only 2 out of the rest 4 logic boards worked after a full recap and DFAC-II clean up. The rest 2 respond to power on button on keyboard but don't chime, screen stays black. Also noticed the 68030 CPU on these 2 boards are running too hot, I can't leave my finger on there for more than a few seconds, which doesn't seem normal. Since we don't have schematic for CC II, they will be a bit harder to diagnose, but I'll keep working on them and see what I can come up with.