Ok, not sure what kinda pics you are talking of, but I took pictures of the main input/power supply pcb so far, and they are at: http://amp.iceregent.com. I am working on getting the 60 watt bulb setup, simple to wire in a lamp with a 60 watt bulb in series with a plug. If I need clearer pictures or different pictures please let me know.

Ice

Ok, I have news to report...

I removed and re-installed one of the main filter caps, the large electrolytic, on the pcb. The resultant operation appeared to be due to the fact that I neglected to re-install the faceplate on the opposite side of the pcb from the heat sink on the power amp pcb. I noticed the metal plate on the table beside the amp after I got that initial cycling result I mentioned in the previous post. I replaced the metal plate, and put the amp back together, and it appeared to work just like it was new. No buzz or anything else, just a clean clear signal. I didnt play the amp at any sort of power or timeframe until a few days later. I played the amp for about 5 minutes, and then suddenly it popped and the 60hz buzz came back and the sound went dead except for the 60 hz buzz. I immediately turned it off, and now have the amp apart again, but, havent proceeded any further. I still do not have any schematic, so I am unsure of how the circuit is laid out. There are ref des on the pcb, but that doesnt help without the schematic. I used to troubleshoot and repair dc-ac power inverters at a company for a living, but, that was with schematics and o-scope etc. Now, with this, I dont have schematic yet and I only have digital voltometer. And , I am only a junior tech, never had any schooling beyond usaf back in 1982. So, I have knowledge of how solid state parts should be but not sure how to troubleshoot right now without knowing what signals should be where. Only thing I can do is probe in circuit for parts that appear to be bad, since there is no apparent visual damage. ANy help? I cannot afford to take the amp to a shop, as I am un-employed at the moment.

Ice

Ok, so, I looked over the mainboard, and found that a lead on one of the main power supply electrolytics had apparently blown a solder hole, and the lead because void of solder. I removed the cap, and checked it with a meter, but the cap checked good, not blown. So, I fathomed the possibility of a solder void becoming overheated and the gasses blowing the solder away from the lead, so I placed the cap back in, correct polarity as it was marked on the board, and resoldered it, and then checked on the power amp section, checking a bunch of caps and the power tranny's on there, but did not find any shorted trannies or caps, so, I put the amp back together and screwed it back into place, and plugged it in.

When I turn on the power, now there is no 6o hz hum, however, the limiter light does a rapid pulsation of about 1-2 hz, and the sound out of the amp without anything plugged in, and with all volume knobs turned to zero, pulses along with it. Not sure where to go from here, since I do not have the schematic for it.

Thank you for the guidance, I will check those things out. I just this morning pulled the amp out of the cab, and am visually inspecting it. I will go over the suggestions, and let you know what my results are..

Ice

I need to fix my Crate BT220 amp, but cannot find the schematics anywhere, not even on the crate site. Any chance anyone would have one?

New here, not sure where to post or even if I can find answers. I have Crate BT220 bass combo, worked beautiful til I went to pick it up from where it was. Took it to rehearsal, and the sound started getting real low, the limiting ligt started coming on, and heard a 60 hz hum starting, which the volume control did not affect. Now, there is barely any sound coming out except for the 60 hz hum, doesnt matter where the volume settings are set to, same sound. And ideas?

Ice