I have a Sony fwd 42pv1...there is no picture or sound but the sreen does come on

SOURCE: Sony Plasma 42 fwd-42pv1 interference / spots

thats a defective light engine..............new tv buddy..............its a known sony problem..........dont listen to thier b.s.

SOURCE: Sony FWD-42PV1 -

I diagnosed the same problem on my FWD-42pv1 as a problem on the Y-SUS board. The fuse on that board was blown, and the board itself was bad (replacing the fuse was not enough to fix it). The symptoms were exactly the same - the LED cycling red/green, and then finally stuck at red.

With a new Y-SUS board, the TV has been working fine for a couple months.

SOURCE: Sony FWD-42PV1 Board Y-SUS 6871 QYH O50C

Ebay just looked at me like, "You want what?!"
https://servicesplus.us.sony.biz/sony-parts.aspx

Has it. 
Bam! Done.

SOURCE: I need to know how

This is pretty easy. Just buy the cables that have S-Video connection. Then plug the wii into the S-Video in on the left side of the monitor. Plug the Audio cables to your reciever or speaker in port on your sound system. Or, the other option is to Find or get a BNC to RCA adapter and use the RCA cable that came with the wii. My TV came with the BNC to RCA Adapter. The BNC location is on the left side of the tv, just above the S-Video connection. Then just change the input selector till you get the right input.

SOURCE: I have a Sony FWD-42PV1 and I will be watching it

This is a common problem on these plasma TV's. The problemresides in the high voltage boards known as the X and Y Sustainboards.. You can purchase them here for a very reasonable price:
http://www.discount-merchant.com/Y-SUSTAIN-FOR-42-PLASMA-TV-PN-6871QYH036A-p/sku9510.htm

The above link is to a Y-SUS board. The X-Sus board is often the 2nd cause of failure and can be found here:
http://www.discount-merchant.com/X-SUSTAIN-6871QZH041B-6870QZE017D-6871QZH052D-p/sku9509.htm

Totest which board is failing, you need to check voltage input to theYSUS board first... Input should be 120V from Power supply, outputshould be above 250V.. Do this test with XSUS disconnected. IF 250+Vexists, then XSUS is damaged. If not, then the YSUS is the faulty part.