PSP turns on with green light but screen doesn't light up
I didn't start my PSP up for a very long while (at least a year or two) and when I tried to power it on, the battery was (quite obviously) dead and I had to borrow it from my friend because my charger is missing, but when I tried to start it up, what I stated in the question title happened and the battery is most likely to be fine as my friend's PSP could start properly with this battery.
Thank you for answering.
Mise à jour (24/08/2017)
Case closed, the screen might be a cause, but I think the real culprit is most likely defects of motherboard. I probably didn't store the PSP properly and the the motherboard probably got a bit oxidized at somewhere that we don't want it to happen. Anyway I'm off for a second hand one and put my old friend on a display shelve.
Is this a good question?