Yamaha RX-V595 display panel stayed on 3~5 seconds then turned off

[Peter Qiu]

Hi everyone,

I recently got a problem with my Yamaha RX-V595 AV Receiver. The front display panel could stay on 3~5 seconds and then shutoff. I powered up again, it happened the same thing.

I started to check the associated DC Power Supplies and they seemed OK. (Presence of regulated voltages, +12V, -12V, +5V, B+ voltage (48V), B- voltage (48V).) Also checking on FL Display power source (Heating Element), it showed 6.7VAC on my multi-meter.

Apart from the above, I checked all Output Power Transistors (2SA1695, 2SC4688 with a multimeter ) all seemed to be OK (No short or open circuit).

Could anyone share with me in fixing the above issue? Thanks in advance.

Peter.

 

[JonSnell Electronic]

Have you checked for DC on the output of one of the amplifiers? Probably in protect mode.

 

[968driver]

This seems to be a frequent problem with these Yamaha series.
Receiver switches in standby for no obvious reason, with or without speakers connected.
No DC voltage on amps.

 

[JonSnell Electronic]

When there is this problem and there is no DC, it is normal to check the clock pulses and micro supply, Peter Qiu has done that so more investigation is required. Dry joints are common.

 

[mbz]

Even though the diagnostic is pointing to dc protection there may be "other"
contributors than the normal failed transistors etc... In the past I've worked back
from the PRD pin on the processor to see what these contributors are. It's been a
while so I can't give specifics but recall some were a little left field. There are
5-6 dead RX-V's in the shed. Maybe you will have better luck.