psp crashes

hi,
i have a psp and when i turn it on it stays fine for a while and when i try to play a game or make a usb connection lines start coming across the screen and the psp crashes and i have to reset it. sometimes i have to reset it a couple of times before i get to the menu again. i know it is a hardware issue but dont exactly know what the exact problem is. i found this video on youtube with the same problem

http://www.youtube.com/watch?v=tBBZRamGYSw

can it be repaired?i want to try to repair it myself if it is possible. but i need to know what exactly the problem is and what parts i need to replace.
thanks

That happened to me when I had some wrong files on flash0

What firmware do you have?, and did you flash some files into flash0?

maybe you can get a theme wich is specifically made for your Firmware, then It wont crash and you'll be able to update to higher custom firmware

i had 3.11 official firmware then downgraded to 1.5 and upgraded 3.90 M33.
im a noob at it and it was only my second psp downgrade/upgrade so i dont know if i did flash the flash0. how do i find out if i did put the wrong files on flash0

If you tried to put a custom theme on flash0, then you may have put older files that make the xmb crash. If you haven't tried to put anything on flash0, forget about that.

Do you have a pandora's battery, or how did you downgraded?

Also, did that happened also on 3.52M33 or 3.52M33-4, cause you have to go through those in order to update to 3.90M33 from 1.50

Maybe it is a hardware issue as you said

i did upgrade first to 3.52M33 from 1.5( i used lumines to downgrade to 1.5) first and i had the same problem. ill try to maake a pandoras battery sometime today and see if that has any better results.
if i still have the same problem after the pandoras battery and it is a hardware issue do you know which piece i would need to find to replace??i dont have a warranty so im going to try everything before i send it back to sony.

i finally got around to making a pandora battery and flashing the psp. it all seems to work for a while but then crashes.i can play games for a little while but then the psp screen goes black and doesnt respond anymore. the green light is still on but no response.
which piece of hardware do you think it could be??