harman kardon avr 507 keeps popping power transistor ?

mr smiths · Guest

hi,

ive got a harman kardon avr 507 amplifier, trouble is the front, left, right and center are ok, surround right ok, surround left not working just get a hum noise and then switches off with protect error, it only switches off when speaker is connected, at first it kept blowing the fuse, also i replaced the d2560 power transistor, for the surround left channel however it just blows the fuse again and takes out the power transistor again? all other channels fine?

anyone help or please advize ?

many thanks
mr smith

Guest · Posted: Tue Mar 08, 2005 2:28 am Post subject:

i should make sure the wires to the speakers are not touching ie shorted this can happen if leads are buried under carpets etc and joined with things like sellotape(scotch tape)

Guest · Posted: Tue Mar 08, 2005 9:37 pm Post subject:

thanks but theres no speakers connected when this happens.

brad · Guest

measure dc voltage at bad chan. output with no load. if over 0.1vdc then driver amp (circuit prior to output) stage is bad. idealy vdc should be very close to 0.

brad · Guest

measure dc voltage at bad chan. output with no load. if over 0.1vdc then driver amp (circuit prior to output) stage is bad. idealy vdc should be very close to 0.

return · Guest

no

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