My PS2 is a SCPH 50001 (I believe version 9 or 10)

Reason I'm changing it is because it does power up but stays in stand-by mode, and for some reason the disc tray won't open.

I've been told that I've blown the LA Chip. Any links instructing how to change the LA chip?

I've also been told to check the fuses. Any help on how the check the fuses? Where to check? I've got a Digital Multimeter but I don't know how to use it?

Thanks