Harman Kardon AVR 270

[R_J]

Re: Harman Kardon AVR 270

Are you sure about those pin numbers? Pin 1 is the 5 volt supply voltage, Pin 2 is ground, pin 3 is the output
But heating never did turn on the fans? It does seem odd that neither fans runs, FAN1_ON and FAN2_ON commands come from ic2103 and should output around 3v to D980 & D970 Fan1 (heatsink) also needs audio at the speakers to turn on the heatsink fan.
Have you tried a processor reset (page49)

[playman]

Re: Harman Kardon AVR 270

My apologies, pin 3 gave me +5v and pin 1 gave me +2v.
Nope fans never turned on, just went straight into shutdown.
Yes I did a processor reset when I fixed the FR channel the first time.
It seems to be running colder after the bias adjustment.

[playman]

Re: Harman Kardon AVR 270

The current heat after 10 minutes running on medium(ish) volume.

[R_J]

Re: Harman Kardon AVR 270

There are two test points near ic2103 (TP59, TP60) you could check the voltage on them, they should be around 3 volts for fan ON, 0 would be fan OFF

[playman]

Re: Harman Kardon AVR 270

They both gave me 0 voltage, even with the fan test shorted (if that matters)

[R_J]

Re: Harman Kardon AVR 270

The fan test would have no effect, these two test points are direct from the processor, so for some reason the microprocessor is not outputing the fan on command.

[playman]

Re: Harman Kardon AVR 270

So I guess the only way to fix it is to replace the processor?

[R_J]

Re: Harman Kardon AVR 270

I don't know if that would fix it, You may need to crank it up for a while to see if they will come on, I really can't be sure.