Hello i have a rca hd52w59 and i unplugged it for about a week now i cant get it to come on. i hear it come on but it shuts itsself off

You are not the only one I can tell you that. I had the same problem with my Phillips 42 in. LCD HD TV.

Here's the problem. The Power Supply Board. I opened my TV up(warranty was up of course) and found several bad capacitors. Phillips and several other companies were sold capacitors that although were highly rated failed within 5 years because of a lack of preservatives. All sorts of electronic equipment is now being effected due to these defective capacitors.
Solutions?
1. Take it in and have it fixed
2. Open it up, check the board for faulty capacitors(bulged or leaking) Buy a new Power supply board and install it.
3. Remove PSB, remove faulty capacitors and replace with compatible new ones.

Hope this helps