Hello,
Some years ago I build an amplifier with two K4005 modules each one in bridged mode. It worked great until some days ago when I was that stupid to connect an audio in with the amplifier powered on. Result of this was one of the K4700 modules told me there was some DC on the output of a channel. I measured this out and indeed, I had about 60V on the output. Before being able to go any further with my investigations T3 died in smoke. I replaced T1 and T3, but I keep on getting the DC on the output. When respecting the polarity it’s about – 2,2V.
Unfortunately my knowledge in this is far from good enough to be able to do more troubleshooting, so any suggestion or advice is welcome. What can be wrong a part from the transistors I already replaced?
Many thanks in advance, Conrad.
As this amp has few active parts, I would replace the driver IC and the output transistors.
Thanks for your advice, I replaced the TL072 and the TDA7250 and it works fine again.
Best regards, Conrad.