I'm having problems with a JVC KD-DV6201 head unit fitted in an Alfa
147. I had the unit installed and working fine, then one morning it
wouldn't power up.
I know that there is power getting to the head unit: If I press the
"disp" key on the front panel of the JVC the clock on the head unit
would illuminate for a few seconds, then go out.
It will also accept and reject discs without any problem. It just
won't turn on - with the ignition turned on or not.

I have a steering remote control fitted between the ISO connector and
the JVC - I've tried removing this, and connecting the ISO directly to
the head unit, but it makes no difference.
I've tried switching the red and yellow wires from the head unit -
battery vs. switched 12v - it made no difference.

The original Alfa head unit (a Blaupunkt) works fine - powers up when
I turn the ignition key.

The previous evening I had been trying to adjust the unit because it
was protruding from the cage, but wasn't aware of damaging anything.

I returned the JVC to the supplier (it's only 2 weeks old). They say
they tested it and found no problem - had it running "all afternoon" -
and returned it to me.

Could anyone offer any advice/suggestions?