Certifiably addicted to DIY.
Join Date: Dec 2017
Location: South 'straya
Originally Posted by xrk971
Did you see or smell smoke on the main amp board when this happened? The fact that the PSU is still good is a great sign because that means you did not put more than 310mA of current into the amp.
2. The main rail smoothing caps C121/124 were reverse biased and probably damaged - lucky they did not blow up like a firecracker as that is the most dangerous thing to happen if your face is nearby. Replace those. In a pinch just remove them and amp will still work - re-install new ones later.
Thanks for the pointers, X.
There as no heat or smoke, the only indication I got of a fault condition was a pulsing voltage - presumably the bench supply or perhaps the voltage regulators detecting a short.
Your point 2 is why I always wear eye protection when energising a circuit outside of a closed chassis.
Thanks again, I'll get some spares on hand and get the chassis finished in the meantime.
The ever growing project list.. :NAP140 Clone, NAD 3020i & 3225PE, JLH1969, TDA2050, Fender 5F2A Princeton, NE5532 Preamp | : VSQC Phunk Style, Retro 50W | Filmosound 601 | SHPA | : Apex AX-14 | TGM-10 | TDA7265 | LM4780
(Last in line)...maybe