Hi Chris,
Sounds like a gamma problem. See if you can find on the T-con, usually near the flexies that go to the panel, a series of test points labelled VGMA1 to VGMA x, or VGref1 to VGref x.
They're relatively tiny and in a single or double row. Measure the volts on each one in sequence. Depending on which end you start at, the V on each TP will slowly increase (or decrease) as you progress through them on a good T-con. May start at around 1V and go up to 21V, but each one must be higher than the previous one eg. 1.5V to 2V to 3.1V is good on the first 3 TPs, but 2V, to 3.1V, to 1.5V on the same TPs is bad. Each one needs to be higher than the previous one through the sequence of TPs. Any reductions or sudden increases will mean bad gamma ie a faulty gamma IC aka AS15 etc.
Don't know what gamma chip is on your T-con, but fault is more likely to be this than a micro. If it's gone to the screen you describe, it may give itself away by being very hot to touch. See how you go - Bruce
