Harman Kardon HK 3490 Completely Dead, No Standby

[NTL1991]

Hello,

I've got a Harman Kardon HK 3490 Stereo Integrated Amplifier and it won't turn on. It's completely dead. With the unit plugged in and the main power switch on the back of the unit turned on, even the amber standby LED won't illuminate. No buzzing, humming or any clicking noises from relays.

The main power switch tests good and mains voltage is getting to the board. From there I'm not sure... Both fuses in the unit test fine.

Would the main power transformer be suspect? What feeds the amber/blue power LED on the front of the unit?

I have the Service Manual for the unit attached. Any ideas where to look next?

Thanks!

Nick

[Khron]

Re: Harman Kardon HK 3490 Completely Dead, No Standby

Page 106, lower-right: small board with power/stand-by LEDs and the power button.

I'd start checking the outputs of the transformer's board, and after that, the voltages that come after the regulators on each board (to which wires from the transformer board go - page 106, bottom middle-right)

[NTL1991]

Re: Harman Kardon HK 3490 Completely Dead, No Standby

Thanks, I'll give it a try tonight and see what I come up with.

[NTL1991]

Re: Harman Kardon HK 3490 Completely Dead, No Standby

I'm getting 0V at both the input and output of the 5V regulator.

I've got 117V at the primary side of the standby transformer, but 0V on the secondary side. I removed the transformer and checked the resistance of each side. About 5 ohms of resistance on the secondary side, open on the primary.

I've ordered a couple replacement standby transformers. We'll see if that's the issue.

Thanks,
Nick