Arfa Daily wrote in message
...


"Stephen Birchall" wrote in message
...
After reading all of the issues regarding the aforementioned mixer, I
decided I had nothing to loose by taking it to pieces and attempting
to test the power output stage. On dismantling all of the plug in
units, it became apparent that both of the output boards had come
loose either by shock or vibration despite being held in by crosshead
screws. After testing the transistors, which were OK, I plugged
everything back in a couple of times to clean the contacts and hey
presto, I now have a fully functioning unit again. So it is sometimes
best to try the simple things first, before spending a fortune.
(previously an electronics engineer had told me it would cost approx
£250 to fix because on his inspection, one of the channels had been
fried. I shan't be recommending him to anyone!)


Nail polish is very good for stopping screws coming loose. Just put a
dollop
around the head of the screw, and onto the surface that it's screwed
against. Very convenient as it is in a small bottle with its own built in
brush. It dries very quickly, and will proof the screw or nut against
coming
loose by vibration, whilst still allowing for an easy 'break' of the seal
with a screwdriver. Also good for sealing preset pots against vibration
movement, or tamper-proofing them.

Arfa


Thats what I use on these Stagepas amp subunits, requires a long thin brush
to apply it. Would be nice to know from the OP whether the screws just undid
or is the plastic thread part stripped ? ie larger screws needed, even if
length is cut down, to give bite

As for 75 squid from Yamaha just shows the advantage to component-level
repair