rol

I don't know why. It might be like Spritzer said. Bought from Mouser, i still have plastic bag from Mouser :)) I removed it out from pcb and measure. I have solved the problem of PSU today, connect to Amp board. Everything is fine, balance and offset ok. 5 minutes later, no smoke, pop or spark - 1 amp board have problem. I measured O+ / GND is 470v. O- /GND ~470v. Offset trimport didn't work. Balance trimport still work. Two C4686 near two 175k resistors quite hot. 3 led still lit up. Where do i should check?

John, It's Xicon 273-442k ohm

Yes, it's 10v when i measured in 20v range Thank you spritzer, xicon resistor is problem, two resistor up to 490k instead 440k

Thank you for advice. Yes, all diodes are ok. I have measured 3 diodes (150 + 150 + 200) 498v in postive rail and 510v in negative rail. Voltage between Lt1021 is 9v in both. I will check the board again if it short in somewhere and replace 440k and 20k resistor tomorrow and see if it can solve the problem. Thanks again.

Hi all. Sorry for my bad english. After 1 year working fine, something gave up in my KgssHv PSU. No smoke or anything blow and i still have sound in the output. But, when i measure the psu board, i get -495v / + 471v on +/- 450 rails. Bias TP 580v. I think positive rail is ok and problem is in negative rail. So, I measured everything from both side and found two difference. First is voltage between 270v zenner. In positive rail is 24v between 270v zenner (D11), voltage between 270v zenner in negative rail is 0v. Another difference is voltage of 8N80C. In postive rail, voltage between D / G legs is 70v, voltage of D leg to -450v output point is 534, volatage of G leg to GND output point is 475v. In neative rail is 39v / 534v / 497v. I had replaced all transitors but nothing changed, voltage is the same. All resistor is OK, no short in PCB on both side if i can see. Anyone have advice for me? After all, many thanks to Dr Kevin, Spiritzer and all contributors to for this wonderful amplifier. Thanks everyone.