ive been having a problem with mosty some slim psps, like for instance the green light would come on but doesnt load to the pandora menu or the powerlight doesnt come on at all. this only happends with some slimpsp 2001's it nvr happends with fat psps though.
If the green light is on, but no menu, it means that the motherboard is a ta-088v3. Pandora doesn't work on them.
how do i get service mode on them?
You can't go to sevice mode.The only way to hack these kind of PSPs is by:
Following this guide, and when you finish follow this. Good luck!