Why when i switch on my psp he cannot read my memory card and he will not turn on?

Hi p_demain,
First you have to figure out what is causing the problem. Try the following steps.

1. Remove anything that is connected to the PSP, including the Memory Stick, battery and any UMD games.
2. Plug the charger into both the wall and the PSP system, then wait for at least 30 seconds before turning the psp on.
--If the PSP turns on, your problem is not with your PSP, but with an accessory that was previously attached.If it does not turn on, your PSP is in need of a repair.
3. Next, unplug the power adapter from the PSP, and firmly place the battery into the PSP.
4. Plug in the Power Adapter once again, and wait at least 30 minutes for the PSP to begin charging, then try and power on the PSP system.
--If the PSP does not power on with the battery plugged in, but it did with just the charger, you need a new battery. If it powers on, do the next step.
5. Place the Memory Stick inside the PSP , and turn on the power. If the PSP does not turn on, but it turned on without the memory, you need a new memory stick.

If your PSP did not turn on during step 2, it needs to be repaired by a qualified technician. I hope everything works out for you. Good luck.