Easy step by step 2.0 -> 1.5 downgrade.
WARNING: This can brick your psp! I will accept no responsibility for bricked psps. It should be near impossible to brick your psp with this guide.
Requirements:
(1) A 2.0 psp. If you have a firmware below 2.0 you can download the update here or
alternatively you can use a UMD with a 2.0 update.
Place the 2.0 update in the GAME folder on your memory stick in a folder called UPDATE, then go to the game icon in your psp menu and load the update (Make sure that you have the A/C adapter plugged in and you have a 100% charge before you update).
Downgrading tools:
(1) The mph downgrader which you can download here.
Some anti virus programs such as Norton anti virus will detect this as a "Trojan.PSPBrick" (dont worry its not a virus!) so you will have to disable your anti virus before you download the downgrader.
(2) A 1.50 update which you can download from here
Installation:
(1) Connect your psp to your pc via the USB cable.
(2) Copy h.bin to the root of your memory stick (the place where the MP_ROOT and PSP folders are)
(3) Copy index.dat to the root of your memory stick.
(4) Copy overflow.tif to the PHOTO folder on your memory stick.
(5) Place the 1.50 update in the GAME folder of your memory stick in a folder called UPDATE.
Step by step instructions:
(1) Connect your psp to the A/C adapter and the usb cable, make sure you have a 100% charge.
(2) Scroll down to the Photo icon in your psp menu and click on it.
(3) Your psp screen will go black and the memory stick light will start flashing. DO NOT TURN OFF YOUR PSP OR DISCONNECT THE A/C ADAPTER!
(4) When the light stops flashing (usualy after 30 seconds) restart your psp.
(5) When you restart your psp go to system settings and check to see if you have 1.0 firmware, if you dont repeat steps 1 to 4.
(6) Go to the game icon and load the 1.5 update.
(7) The update will stop at 99% and give you an error message, DONT PANIC! Just restart your psp.
(8) When you restart your psp you will see a data corrpt message, just press o to continue
(9) Your psp will ask you to enter date and time etc.
(10) You now have a 1.5 psp!
(11) You can now delete the 1.50 update and the downgrader.
(12) Have fun with your 1.5 psp!
If you have any questions eave them here and i will reply asap.
