JVC 4VN-880 - Humm an issue

[surteess]

I have owned the unit since 1976 (yes one careful owner!! - still have box + paperwork)

So without a service manual on the 4VN-880 unit I am a little lost.

The unit has developed over the past 3 months an annoying "background" humm - most noticable at low volume (and no volume).

It does not matter what input or mode output I select it is still there.

I deduce that it must be a power supply issue, but without circuit diagram I am lost as how best to tackle the problem.

Anyone ever had a similar issue with same / similar model?.

thanks

Steve
(in Auckland, New Zealand).

 

[mandrix]

You can try this site, I don't know what all is available but it came up on a google search.
http://www.hifiengine.com/

 

[surteess]

thanks - for that have tried them, but no info...bit like Wiki - depends on who issues what.

 

[mandrix]

Too bad. They have a lot available. I was able to get schematics for my old Sony.

 

[surteess]

All fixed now

- it was a mounting post for pcb support, that was also used to ground the pcb - the post had got a bit of rust on the washer - hence bad grounding, so took apart & cleaned surface then replaced with new washer & hey presto fixed!!!

(going to go around and do the others this weekend - as it is a simple job to do).