grandpaslab
Active Member
I've got a 950 that came in with a blown output, blown main fuse. I've done the following:
Unit now powers up but is in protection. Voltages are low across the board, e.g. 28v at the outputs where it should be ~49v.
Can anyone suggest next test(s) to localize the voltage issue?
Transistor subs were as follows:
Main amp
2SC1628 -> KSC3503 (Q7, Q8)
2SA818 -> KSA1381 (Q5, Q6)
2SD381 -> KSC2073 (Q3, Q10)
2SB536 -> KSA940 (Q11, Q12)
Power supply
2SB507 -> KSA940 (Q2)
2SA720 -> KSA1013 (Q4, Q6)
2C1318 -> KSC2383 (Q3, Q5, Q7)
2SD313 -> KSC2073 (Q1, Q8, Q9)
2SC869 -> KAC2073 (Q10)
- replaced all outputs with onsemi subs
- replaced all transistors, diodes and electrolytic caps on the main amp board
- replaced all transistors, electrolytics on the power supply board
- replaced filter caps
- replaced main rectifier diodes with 621-10A04-T
Unit now powers up but is in protection. Voltages are low across the board, e.g. 28v at the outputs where it should be ~49v.
Can anyone suggest next test(s) to localize the voltage issue?
Transistor subs were as follows:
Main amp
2SC1628 -> KSC3503 (Q7, Q8)
2SA818 -> KSA1381 (Q5, Q6)
2SD381 -> KSC2073 (Q3, Q10)
2SB536 -> KSA940 (Q11, Q12)
Power supply
2SB507 -> KSA940 (Q2)
2SA720 -> KSA1013 (Q4, Q6)
2C1318 -> KSC2383 (Q3, Q5, Q7)
2SD313 -> KSC2073 (Q1, Q8, Q9)
2SC869 -> KAC2073 (Q10)