I'm surprised you can get the PS3 to boot up at all with the YLOD. Usually the system will turn on, then beep, then shut itself right back down. A YLOD is usually caused by a hardware fault of some type mostly caused by overheating.
Normally, 9 times out of 10, a YLOD is not salvageable without extensive knowledge of the PS3 system. Unless you can pin-point the source of your problems, I'd say the best course of action is to send it in for repairs. Sorry bro.
