hight idle current HARMAN amplifier

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
hi ,

I have a pb with a left channel of Harman Kardon pm655 vxi :
idle current (vr403) is > 30 mv ( mesuring = 80 mv betheen tp4 and tp5) . typicaly the value is equal to 6 mv on the right channel.
after 2 hours Q441 et Q443 falls down .
I turn vr403 to minimum : 40 mv
VBE voltage on q437 and q439 equal 0 volt ...
What is the pb ?
very thanks
 

Attachments

  • sans titre.gif
    sans titre.gif
    62.5 KB · Views: 153
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.