Newbie with a faulty C320BEE

[kard133]

Hi, I have a C320BEE which will not come out of standby. When the power button on the remote is pressed the red led lights up and returns to amber. There are no obviously burned components on the board, the only thing I have found with my limited electronic knowledge is that the 46v rail on the rectifier board is outputting 84v. This is with no speakers or other units connected to the amp.
I have 36v leaving rectifier D45, and 30v leaving rectifier D41. I have checked the values on the resistors and they appear to be within tolerances, I de-soldered a few that gave off readings but once out of circuit they were fine. They were replaced with silver solder. I do not know how to check the capacitors, diodes or transistors, but I have a multimeter with a diode check/continuity function, the service manual and access to a comprehensive range of tools.
Any help or suggestions would be appreciated.

[kard133]

II have also found that capacitor C436 on the board has a value of 10uf 160v written on it, whilst in the service manual it states it should be 100uf 6.3v. I was given this amp in a non working order and do not know of its history.

[nigelwright7557]

You need to go back to basics.
Find a schematic.
Check the power supply on its own. Could be faulty capacitor(s) or bridge rectifier.
Check fuses to amp, if blown check output transistors.

[kibi]

My C320BBE is also exhibiting the same symptoms.
One of the Power Supply filter capacitors had ruptured (the big white NAD labelled ones). All fuses are still OK.
I am waiting for replacement capacitors to arrive and I'll let you know how it goes after I have installed them.

[kibi]

Mmmm, OK. Not so good.

I have replaced the 15000uF caps. on the PSU board. Still won't come out of standby.
I have service manual, so I'll have to take it from there unless anyone else has some good idea's.
I bought this amp 7 years ago and it stayed on (green LED) for 7 years. It blew up whilst I was in Poland on holiday. It's not had a bad run, but it'd be nice to have it working again.

[kibi]

I chopped my thumb half off last week, it's been sewn back on, but I am not allowed to go to work. I took advantage of the time off to figure out whats went wrong with my C320BEE.

I found R45 (33R 0.5W resistor) burnt open circuit. This resistor is part of the +18v supply regulator. The +/- 18v is for the preamp modules among other things.
The +18v rail was reading 1.2 Ohms (let's call it a short circuit for arguments sake) whereas the -18v rail was not. That would explain why R45 burnt up.
I traced the source of the "short circuit" to CB32 (the preamp module towards the rear of the amplifier).
I removed the module and after some poking around found that C68 (100nF Monores capacitor) was reading 1.2 Ohms across it.
I replaced that capacitor, put the module back in place and replaced R45.
Viola! It's working and both of the +/- 18v rails are within 0.4v of each other with respect to GND.
So C68, a tiny little capacitor in an obscure place brought the whole amplifier to it's knees.
IMPORTANT TO REMEMBER: The faulty C68 in my case was located on one of the preamp modules and not on the main board. Both of the modules are made the same, and they have the same component location numbers on them.