here's a paragraph someone seemingly smart writes online,
source=http://experts.about.com/q/1749/3551382.htm:
The reason it shuts down is because of excessive current drain, thus
tripping the protection circuit and opening the relay feeding the outputs.

The output transistors (mounted on heatsinks) is the likely cause. You will
have to replace them.

This is 80 to 90% of cause for failure in audio amplifiers.

Make sure you know how to do it; they are critical for proper mounting and
heat transfer.


"JVC dude" wrote in message
...
The transparent plastic cased object is the speaker protection relay
probably (or the main power rail switching). It should click in 5 seconds
after powering on - unless there is a fault condition such as a failed amp
output where high DC voltages are sent out and would otherwise damage your
speakers.

You say there are 2 large black plastic modules with 10-16 pins? probably
with STK xxx on them. Its most likely that one of these has failed.
You ideally need to establish which has failed- its unlikely both have. Is
1
getting hotter quicker? this is probably the dud.
Now If you've no experience on electronics I can't condone you trying to
replace this yourself- you need to unsolder it, check for other failed
parts
nearby etc and check the new one is running stably.
Take it to a techy really
Hope this helps
Andrew