Repairing LCD TV - Westinghouse LTV-32W3

I am trying repaire my LCD TV Westinghouse LTV-32W3. I purchased it 1
1/2 year ago - it worked OK for about 1 year. After warranty expired
it works OK for about hour, after 1 hour the following symptoms
appeared:
http://www.evkosystems.kgbinternet.com/evkosystems/tv/Bad-TV-2-1.wmv
The TV on the left is a good one, on the right Westinghouse LTV-32W3

I come to conclusion that some parts in the TV are getting too hot. To
test my theory I removed TV's  back cover to allow better air
circulation - now TV is working without problem. What I want to do is
to install small fan to make a better cooling.
I am not a TV technician, so here are my questions:

electronics parts that are getting hot are enclosed in a metal case:
  http://www.evkosystems.kgbinternet.com/evkosystems/tv/IMG_0014.JPG
here electonic parts with metal case removed:  
http://www.evkosystems.kgbinternet.com/evkosystems/tv/IMG_0017.JPG
I guess the metal case is to prevent electromagnetic transmition - can
I make more holes in a metal case without causing electromagnetic
interferrence?

I plan to put inside a small fan, similar to one used in computers -
can you recommend one?
Can you recommend simply converter from 110 AC to 5V(?) DC to power
this fan?

Thanks,

Zalek