NAD 7140 repair-HELP


I recently picked up a NAD 7140. When plugged in it lights up and the relay audibly clicked, but no sound from any source or from headphone jack. I found the preamp does work with another power source. I understand that NAD products have had reliability issues. So, is anyone out there aware of a common fail in this line of receivers, where is the first and best place for me to check? I will try DIY repair as well with some direction, where to start? I don't see any obvious leaking caps or fried resistors. I also cleaned pots, buttons, and connections with electrical cleaner. One last thing, when I opened it up there were two slow burning fuses burnt out, neither being the main power fuse. I replaced them and they held when I turned the unit on. I may sound like I know what I'm doing, but I am brand new at tackling a self diagnosis and fix. I do find it a challenge that I want to take on and learn something along the way. I have scoured the internet for answers without any success.  
I hope someone in this community can help and give direction.
Thank you!
tntate
imhififan,
Thanks for the link and precaution. I will not fry myself!!! But, I must continue on this journey until I succeed or at least gain understanding of basic troubleshooting.  I like reviving the broken...
wish me luck!
I will post when I succeed.
Did you ever find a solution to your 7140 with no sound output?
 
I'm in a similar situation with a 7130 with no sound output (albeit very minimal output on full volume)

I've sprayed everything with contact cleaner, and can't see anything visibly wrong, but I'm desperate to find the problem.

Let me know if you did manage to sort your 7140, and if so, how!

Many thanks

Wilf