sony PSP - no display. + another PSP does not boot

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I have a sony playstation portable that had no display.
the unit was dropped, then the dispay stopped working. I replaced the lcd and backlight, but still no image appear. The psp does boot. it can be heard and everything appears to be functional except the display.

The 2nd psp I have was incorrecrtly flashed. It powers no, but nothing other than power. it appears to have been firmware updated, but it failed.
can the firmware chip be reset somehow to factory?