42LG7000 intermittent start up problems

[GGTVBD]

Got this 42LG7000 in for repair which, more often than not, won't start up. Power supply can be heard trying but all voltages are present and correct. Swapped the power supply PCB and it's confirmed the fault don't lie there!

Suspecting the main board but obviously don't want to take the plunge based on an educated guess(!).

Anyone any ideas?

Any LG account holders fancy trying LG tech for me?!

Thanks lads.

[tv tony]

all lg spares require full model name inc the eauk or sim no. ill do it with pleasure

[alpinemobile]

If the red led blinks then it turns blue without the lcd panel lighting up then this might be your problem.
This eprom chip is faulty and only works when it is cooled down. The chip is rectangular and located at the right of the main processor. It reads HYNIX      KOR , HY27US08121B , TPCB       839F , M7TE0277Q3. You can see it circled in this picture  imgur.com/bjyCNCq . Easiest way to cool it down is to use a can of compressed air (that is used for cleaning keyboards) and to spray the chip with the can upside down. (you can drill a hole in the back cover directly above the chip). When spraying with the can upside down the air that exits the can is very cold.
Cheers!