Welp, I've got a problem. I bricked my PSP slim for the third time, so I decided to get a Service Tool. It arrived today so I inserted my battery, everything went fine. I used my sister's PSP to make an MMS, inserted them both into the Slim, aaaand... Nothing. Well, almost nothing - the green light lit up when I inserted the battery, but the screen remained blank.
Now, as this was not my first time I had a couple of ideas up my sleeve which I tried. They all resulted in precisely the same thing, which slightly surprised me as I expected a little variation:
-Using a computer with windows XP instead of Vista
-Using a different memory stick installer (I had been using PSP Pandora Deluxe, I tried using the Catb50 flasher)
-Using a different battery (I had been using my slim's; my sister's was a phat so I tried that. Note that I was able to change the phat battery back to normal with the Service Tool, which might suggest that the Service Tool is not the problem)
-Various combinations of putting the battery in, putting the memory stick in, and holding the left trigger (which I assigned to Desperar Cemeturio v8 in the PSP Pandora Deluxe menu)
-Formatting the memstick and changing the battery back, and starting again. I have done this a LOT.
Extra info: My sister's PSP is non-homebrew. I am using an old 1GB memstick as the MMS - it has been a working MMS in the past. The Slim has been homebrew'd in the past. The slim battery has never been a pandora before, but the phat's has. One odd thing is that the Service Tool's instructions say you should put the battery in first, then the memstick, while most resources for the MMS files say it should be the other way around. It's unlikely to be that though, isn't it?
I'm really worried that the Slim is a permanent brick. How would I know if it was? I guess I COULD try using the battery and memstick on the phat PSP to see if it works, but I'm terrified of bricking that one too. Please help, PSP homebrew has been my main source of gaming for three years now!