1090 problem

[befar]

when i push the speaker button,1or two, the left channel blowes a fuse,also the volume does not completly turn all the way down on the other channel,does anybody have a thought could these problems be just the volume pot?:scratch2:

 

[airtime]

Disconnect the speakers and try again. But it doesn't really sound like a speaker load problem.

 

[catrafter]

If F701 (I think that's the left side fuse) is blowing, then your left side power amp most likely has shorted outputs and needs repairing. It is probably sending the power supply rail voltage to the speaker. Not good!
Check EchoWars' thread to see how to measure DC offset.

The volume pot problem could be cured by a simple cleaning.

Tom

 

[airtime]

You can unscrew the output transistors, remove them and try and see if the fuse holds. Also don't forget to mark the transistors to put them back in the same order.

charles

 

[avionic]

Pull the left channel outputs one at a time and check each one with a multimeter for shorted collector to emitter junction.

 

[befar]

ok going to pull the out puts,cleaned the pot before trying and again after 2 fuses thanks to all for responces,off to get more fuses,i read where the volume problem is common in this unit as reported in older threads

 

[airtime]

Yes, but a bad volume control wouldn't blow a fuse. I would also check the voltages coming off the power supply board if you have a service manual.

 

[befar]

does anyone have a link to download manuals for this unit i think it looks like i am gona need one

 

[airtime]

PM I have it and can email it to you.

charles