Denon Receiver won't power on

[rick79]

Denon DRA-435R wont power on. Looks and sounds dead, No display, No clicks, also there is no power on the rear "switched" Ac outlet when pushing the power button.
I checked the fuse and it's good. What would be the next thing to check on the board?

 

[rjenkinsgb]

You can download the service manual from this page:

Denon - DRA-435R - Receiver -- Opweb, the free download archive

Huge archive for manuals, schematics, service manuals, pdfs, repair guides and handbooks

www.opweb.de

The main schematic is on the last page; I'd start at the bottom right of that and check the AC voltages from the power transformer to the circuit board (the oranges, blues, black & reds).

If everything is OK there, check the outputs of the rectifiers, across C503 and C510.
Then the low voltage regulator output, across C644 and so on.

And check the 5V supply to the microprocessor at the top right; that appears to be the source of the "P.On / Off" signal that switches main power and the aux power socket relay.

It's a matter of elimination..

It has electronic on/off switching so some internal supplies are permanently on, as it needs the microprocessor active for that to control the main on/off function.