I read through some of the old posted and didn't see much on the 3.51 M33 Upgrader.
Here's what happened. I have two psp that I installed the official 3.50 upgrader on.
I then used the 3.50 downgrader to 1.50 then 3.40 oe-a easy upgrader to have the custom
firmware. Then I used the 3.51 M33 to upgraded to that firmware.
My two psp handhelds work perfect. But when I tried to do the same method on a friends psp
the M33 upgrader didn't work. From 3.40 oe-a I started the M33 upgrader and the screen went black
and that was it. THe battery power was at 85% and it was the same file that I used on my psp's.
Now when I turn the system on the green power light turns on but the screen remains black and
after about five seconds the the power light shuts off. I have tried holding the right trigger button
but get the same reponse.
Am I screwed or can I fix the problem?


Thanks.

It doesn't sound good.
I don't have much experience with (semi-)bricks, but you could try taking the battery out for a while and then putting it back in and trying to load recovery mode today.
Hopefully other people on here will have some better suggestions.

When you're downgrading, you must always know what motherboard version does the psp has because it's important, using a wrong downgrader for wrong psp motherboard is deadly. so what is the psp motherboard version your friend has?

well for one he said he was upgrading form 3.4 oea so he already downgraded and was attempting an upgrade so motherboard shouldnt matter. and two there have been a few reports of 3.51 bricking some psps. one guy claimed he finished the upgrade entered the recovery and it bricked when he exited recovery. it seems like 3.51 is corrupting the flashes somehow. but as to why its happening i have no idea. try what adw said maybe leaving the battery out will help. its helped other people for some reason. were you using a real memstick during the upgrade? or like many others is it fake?

it doesnt seem like you bricked it because you just ran the updater, unless you got some kind of text and then started try entering the recovery mode and see if that works if not it is possibly bricked

Some have found luck in removing the battery as adw stated. Try that and see if it turns on. If not take the battery out again and try to go into recovery right away instead of turning it on. Hopefully you can access the recovery.

The battery thing ALWAYS works for semi-bricks, so if that doesn't work, according to my experiences you have a complete brick. In that case, I'm sorry but you can do nothing. Try turning it on, and when the green light flashes, quickly take the batter out, that should do a total reboot.

O.k. I have tried leaving the battery out for a while and putting it back and got nothing.
When I turn it on the green light stays on. It never flashes.
Someone had mentioned trying to get to the recovery WITHOUT turning the PSP on.
How do I do that?
When I started the M33 upgrade I never got any wording. I just pushed the X button to start the
upgrader and the screen went black like normal and then after about ten seconds the PSP turned off and
hasn't turned on since.
I am pretty sure that I have a brick and I guess I can live with that. I have already replaced his with a different one
so he's cool with that.
Thanks for the help and if anyone wants to buy a "slightly used" PSP let me know. (just kidding)

Lmao I WANT ONE!

sorry dogg