Hi everyone,

I've worked on a number of valve and solid sate amplifiers over the years but never had much success with fault finding on DC coupled power output stages. For example, on occasions I've found the power output transistors blow, replaced them and checked all other transistor/diode junctions and all looks O/K. Switched on and the expensive power transistors have blow again.
I was just wondering if anyone can suggest a clever (and safe) way of fault finding on these DC coupled circuits to avoid having to keep replace expensive parts.
Regards
Geoff