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dirtyb15 said:Okay, one of the two diodes that i saw disoloration is shorted. I think it is a 1n535. I have no problem replacing these, but what would cause it to short like that? I made sure there were no places the board was grounding out or anything like that.
dirtyb15 said:cr56 and cr57 on the pcb. I dont have the schematic you sent me with me so i assume these labels are on the shemcatic also.
dirtyb15 said:I had my multimeter on the wrong setting, neither is open or shorted. I have 16 and -16 at the correct test points. So what should i look for now? All i get is a loud hum. Does not change with volume, guitar inputs or anything.
I apologize for turning this into such a big post, I probably should have just taken it to the repair shop
dirtyb15 said:Well its definitely not 0. It is at 40V.
dirtyb15 said:Well i did not leave the amp on for very long so i hope my cabinet is okay.
Upon closer look at the board, i noticed that cr27 diode was not near as low to the board as the other 3 on the heatsink bar. I pulled on it a bit and sure enough it was not even soldered in, or had broken at the joint. Could this have caused it to blow? Is it worth trying to repair the output stage? Thanks again, sorry for all the questions.
dirtyb15 said:Soldered the diode back, but no lottery wins ever for me
I have shorts on both q13, q14, and i suspect cr38 is also damaged ( will will pull it to be sure.)
dirtyb15 said:I was quick when i did my measurment and must have had my probes backward. I just verified it is -40V.
dirtyb15 said:well i picked up a new TIP147 at the local electronics shop. Soldered it in, checked everything over once and powered it on. Measured output and had 0V. Started smelling something so i checked again and i was at -40V.
Powered it off and took the new one out again. The other tranisistor is now shorted.
dirtyb15 said:cr25, cr26, cr27, and cr28 all checked out okay.
Any other obvious components to test?