I picked up a Sunfire True Subwoofer MK IV for free as it had a bad hum. Most of what you read says replace all the caps and you are on the way. No joy. It went from bad hum to dead short after recap. After many searches I found a few clues as to the issue. Here is a list of what I found.
Q12 2SC4793 Tested good but replaced as it was already removed
Q13 2SC4793 Unknown/faulty
Q14-Q17 PNP 2SA1302 = MJL1302AGOS-ND NPN 2SC3281 = MJL3281AGOS-ND one of each shorted replaced all
Q18 2SA1837 Unknown/faulty
Q19-Q24 Mosfets IRF640PBF two shorted one on each rail replaced all
D10-D13 1N4148 all four shorted replaced all
JP1-JP2 0ohm resisters smoked
I hope this helps others. I have pdfs of the info I found on other forums if anyone whats to read them as well.
Tony
Q12 2SC4793 Tested good but replaced as it was already removed
Q13 2SC4793 Unknown/faulty
Q14-Q17 PNP 2SA1302 = MJL1302AGOS-ND NPN 2SC3281 = MJL3281AGOS-ND one of each shorted replaced all
Q18 2SA1837 Unknown/faulty
Q19-Q24 Mosfets IRF640PBF two shorted one on each rail replaced all
D10-D13 1N4148 all four shorted replaced all
JP1-JP2 0ohm resisters smoked
I hope this helps others. I have pdfs of the info I found on other forums if anyone whats to read them as well.
Tony
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