freakquincy
New Member
Hello, first time posting here. I have both a Pioneer SX 525 and SX 939 that are experiencing the same symptoms: After a few minutes of use, they develop a loud static/crackle/thunder from the right speaker. From what I've read this may be shorted/bad transistors on the power amp board, as input source and volume do not affect the problem. (I guess this is called the 'main amp' in the 525 manual?) . In any case, I did search a few threads on here, but just wondering if anyone can point me to a definitive repair/rebuild thread for either of these models. I think I may try to tackle the 525 first, due to the simpler design, but on the other hand the 525 used to be my dad's and I don't want to wreck it. But cracking open the 939, man that thing is busy inside.
This may be a dumb question, but on a receiver like the 939, do you have to sometimes de-solder most/all the connections to some of the boards to get enough room to work on them, or are there other tricks to gain access?
Best transistors to sub for 2SA572-4B, 2SC1318-R, 2SA720-R, 2SC789-O... Do I need to replace the diodes and varistors too?
Which caps/components to replace for complete rebuild, but without going overboard? Anyone have complete parts lists for digikey or mouser or...?
FYI I do have some experience with tube stuff (Hammond), but this will be my first venture into more cramped solid state territory...
Any help, suggestions, bashing, and insults will be taken under consideration.
This may be a dumb question, but on a receiver like the 939, do you have to sometimes de-solder most/all the connections to some of the boards to get enough room to work on them, or are there other tricks to gain access?
Best transistors to sub for 2SA572-4B, 2SC1318-R, 2SA720-R, 2SC789-O... Do I need to replace the diodes and varistors too?
Which caps/components to replace for complete rebuild, but without going overboard? Anyone have complete parts lists for digikey or mouser or...?
FYI I do have some experience with tube stuff (Hammond), but this will be my first venture into more cramped solid state territory...
Any help, suggestions, bashing, and insults will be taken under consideration.