Hi,
Here’s the guide for PSP 1000:
[guide|1783]
You haven’t stated your model, but the process will be similar.
If your screen is broken then this guide should help you.
If the screen won’t turn on, then you probably have a fuse shorted that can be replaced or bridged with appropriate fuse wire gauge.
You can find YouTube videos on how to repair blown fuse in PSP.
If you don’t have tools/skills then take to repair shop for assessment and/or replacement fuse.
Hope this helps