Harman Kardon AVR 25II Relay keeps ticking

[R_J]

Re: Relay keeps ticking

I see no reason why there is no audio, It could be a simple as the tape monitor switch being pushed, Do you have a scope? if not do you have another working amp, try connecting the pre out to the input of a working amp, that would check if most of the pre circuits are working. You could also supply a signal into the "main in" to check the amp circuit, but this signal would need to be low level as you would be bypassing the volume control

[DjKrish]

Re: Relay keeps ticking

Ok heres the thing. Ive tried preamp out, no sound nothin on a different amp.

I connected my headphone and the relay clicks, i can control the volume yes but no music nothing, just a plain faded tuner sound on any source i choose in the amp.

Even i plugged in my hp and cd player to the cd port, still nothing.

[R_J]

Re: Relay keeps ticking

If you plug the cd player into the main in do you get sound from the speakers or headphone?
does the tape1/tape2mon switch have any effect, if it is in mon it will cut the sound from other inputs
on page 44 of the manual do you have +15, -15 and +6volts?

[DjKrish]

Re: Relay keeps ticking



You see on the board, those i marked red, is the leg thats receiving nearly 50v and goes into protection. Ive popped out the leg to stop the protection. But the circuit base still has the near 50v. So in this casde its not the transistor thats faulty. Somewhere else something has a short.

Ive plugged in cd player into cd and plugged in my headphone, i can hear a bit of music with full volume. Just a bit, like 10% at 100% volume. Still nothing on speakers. zero.

The moment i shut off the main power plug, i test the caps with multimeter, the caps voltage getting killed really fast. I usually use a light bulb to short the caps to kill the voltage but before i could kill it, something else killing it pretty fast in seconds

[R_J]

Re: Relay keeps ticking

so at this point all you want to do is repair the faulty channel, so check the driver transistors in that channel and also check for open resistors.
I thought you had the schematic?
You say you get 50 volts on the point you marked in red, Is that +50 on one and -50 on the other? you could have shorted Q260L and Q261L. or maybe open R272L

[DjKrish]

Re: Relay keeps ticking

Hi RJ, the schematic i downloaded seems a bit messed up and half in everything. Anyways managed to get some info.

Q263L is - A1386A
Q262L is - C3519A

While checking voltages, suddenly R263L AND R264L started burning most probably cause A1386A and C3519A 2 left legs are still soldered and only the last right leg is unsoldered

Should have unsoldered all 3 legs while checking for voltages on other parts. Thank god didnt fry anything else as i unplugged before more damages. Now i gotta replace these resistors and check for any transistor shorts on L channel.