that seems short and fast. Change ur title thread to be more descriptive like " Help on Downgrading 4.00 firmware", b4 the mods close this thread.
Since, u have 4.00 u need to downgrade ur psp and install a custom firmware. First, u need to downgrade in order to install custom fiwmare. So ...
To downgrade or unbrick your PSP, u need the Pandora's Battery. There is three ways to get the Pandora Battery.
1. Find a someone who has a Custom Firmware that is willing to let you borrow their psp. You will use his psp to softmod the battery. Meaning using software to make the Pandora. If you willing to do this, follow this guide:
GUIDE
2. Hardmod the battery. Meaning that you have to open that battery up, and pulling out a pin. Note that if you pull the wrong one, your battery would be messed. If you are willing to do this, follow this guide
GUIDE
3. The most safest way, is to buy the DATEL tool battery. It is already a premade pandora battery. If so, follow this guide or use the same guide on the second step.
GUIDE
the tool battery is your best bet google deal extreme and searh for pandora battery its 10.50$ usd+free shipping and it came in a week id would link it but im on my psp. on amazon.com you can also get a 512mb pro duo for 8.95$ usd +free shipping( its good for a dedicated mms
