in red circle is optical toslink and coaxial and the blue circle is audio out rite?

Hi guys, need some advice here.

I've got a PS3 bought about 3 years ago when Sony Malaysia first started selling them officially. Lately, my 5 y.o. son been playing a lot on it and a problem developed. When playing any disc game, the ps3 would shut down a few minutes afterwards and theres a red light blinking. I can only restart the ps3 manually after that and theres usually a message "Your PS3 wasnt shut down properly....bla bla" before the normal start screen.

I think its a overheating problem. My questions are:

1. How much does it usually cost if i send it to Sony for repairs? Is it worth sending it since some people reported that their problem wasnt fixed when they got their ps3 back.

2. If I buy a new slim ps3, can I use my 500gb hd from my fat ps3?

Thanks for any input.