Panasonic Viera 55" No Picture

Hi all.

I've just purchased a 55" Panasonic Viera in the hopes of a cheap quick fix project. The power works fine, TV turns on and the back lights work perfectly, also no issues with audio - but there's nothing on the screen.

I've shone a flashlight over the screen whilst on and getting no images at all.

I've tried disconnecting the power for 5 minutes, pressing the power button to drain the residual energy out of the boards and then plugging back in.

I've replaced the TCON board but still not getting anything. Is there anything further I can try?

I haven't found any damaged/inflated capacitors on any of the boards and also no sign of overheating/burn marks on the boards, so can't see anything glaringly obvious.

Anything else I can try?