Black out tv after thunder rain

hello: I have a sony kv27s20 tv and suddenly after a rain lightning thunder it went black. It was turned off but the TV was connected to the electrical outlet so the stand by mode was on. After that the TV is not turning on, stay black.

I took it to the technnical service and they told me that the best way to repair it is replace the main board ( A board I guess ).

I am looking a store where to purchase this part. Actually I do not have the part number so If anyone around know the part number I appreciate if it can mail it to me.

Any other idea about this problem will be helpful.

Thanks in advance
Sturges