Thread
512k repair
I got a 512k from a friend. He got it from someone, and that one completely took it apart. Also the case is painted with some ugly beige Apple Snow White wannabe color, that needs removing. Brake fluid prehaps?
The logic board is modded, there is a MagicSCSI card installed.
Analog board has two capacitors replaced with some 100uF 385V caps. They are much too big and also have quite high ESR (they are dated 21/90). What values were they originally? Locations C38 and C34.
Also there are CR22 and CR23 that were replaced sometime. The replacements are 1N4004, what were there originally?
There is also one clip broken on the anode cap. Will the CRT function without this clip, or should I get a replacement one somewhere?
I haven't powered it on as I would first try to repair any botched repairs.
The logic board is modded, there is a MagicSCSI card installed.
Analog board has two capacitors replaced with some 100uF 385V caps. They are much too big and also have quite high ESR (they are dated 21/90). What values were they originally? Locations C38 and C34.
Also there are CR22 and CR23 that were replaced sometime. The replacements are 1N4004, what were there originally?
There is also one clip broken on the anode cap. Will the CRT function without this clip, or should I get a replacement one somewhere?
I haven't powered it on as I would first try to repair any botched repairs.
Ok, I replaced the capacitors (100uF 250V) and diodes (used the 1N4007s).I used the brake fluid on the case and the old paint is starting to peel off easily 
After that, I tested it. It chimed, but the screen remained dark. Also the cathode heater in the CRT was glowing quite strong.
Next, I wiggled around the anode cap, and now it won't chime anymore. It just makes a strange chirping noise. The heater still glows rather strongly, I forgot to mention that this is an International Analog Board version configured to 230V.
I followed The Dead Mac Scrolls, but the checks that Larry Pina suggests revealed nothing broken. Perhaps the problem lies in that broken anode clip?
Thanks
After that, I tested it. It chimed, but the screen remained dark. Also the cathode heater in the CRT was glowing quite strong.Next, I wiggled around the anode cap, and now it won't chime anymore. It just makes a strange chirping noise. The heater still glows rather strongly, I forgot to mention that this is an International Analog Board version configured to 230V.
I followed The Dead Mac Scrolls, but the checks that Larry Pina suggests revealed nothing broken. Perhaps the problem lies in that broken anode clip?
Thanks