Facing TV Problems? Ask a TV Technician.
Hi, I'm Pete. Welcome to JustAnswer! I'm reviewing your question now, and will post back with your reply ASAP.
Thanks for getting back to me.
The TC-L42ET5 and TC-L55ET5 do indeed have the same Main Board (A Board) - part number TXN/A1SLUUS (TNPH1006UF).