LS400 Intermittent Pioneer Head Unit

[MHT]

I've had an ongoing problem for a while with my Pioneer head unit - it started off that it wouldn't turn on when it was cold during winter but would be fine during summer.

More recently it just won't turn on, but every now and again, say 1 in 100 trips, it will just start working again like there was never a problem.

I remember reading in the past something along the lines of intermittent problems with the amplifier could stop it working but I can't recall essentially what the situation was. 

I spoke to the car audio place that I used recently for another car and they suggested a Bluetooth system that would work with a new 5 channel amp, leaving the head unit as an ornament. I'd rather get it fixed - has any one had a similar problem, or more to the point found someone that knows their way around it to fix it? 

I've attached a picture of my actual head unit for clarity.

Mark