harmon kardon 930 twin power receiver -- heated up
Dear friends in HIfi Engine,
I have a problem with the above receiver and seek your advise on the likely cause and what shd be done to rectify this problem.
proble area : The left channel out put heat sink is very hot like an electric iron. So is the transistor.
I checked the voltage at the speaker out put it was Rt channel about 5 mv and left channel 78 mv.
This problem comes erractically -- sometimes it is normal and some times after i on it for about 20 mins , the left side got heated up very fast. The other channel is ok. It seems to be something is not stable and drifting.
My question : Can this issue fry my speaker ?
Can this be cause by the biasing ? if so how can i adjust the biasing or other areas i should look at.
This receiver has been more than 30 years old, should i replace the two pots that control the speaker out put voltage.
Hope to receiver your advice and guidance on how to tackle this problem.
Thank you and best regards,