No sound picture

Hi there i would like advice for my vistron 37 inch TV, the TV was working fine until yesterday powered on from the mains socket, the led power light comes on no picture or sound tried to power off from the the TV power button on the side of the TV nothing happens still stays power on, the led is blue, when it standby it goes red it will not go into standby, i have noticed the power led flickers once say every 13 seconds i looked on the net and it say it could be the power board GPAC-211424A REV 2.4 which you have in stock if i purchase from you and the fault is not the power board and it is the main board can i return the board Regards GARRY RIDYARD