BB9900 keeps on turning off/freezing

Hello everyone,

I'm absolutely desperate: since last night, my BB 9900 bought 1 year and a half ago keeps on 1. turning off 2. if not, it just freezes with the most annoying clock on earth that you're now probably all familiar with. It happens only after like 30sec/1min everytime I do a battery pull so I just can't use it basically.
It's fully charged and after many battery pulls the whole day, of course the battery level started to lower but I put it on charge again and it got fully charged and it doesn't empty weirdly fast so I don't think this is a battery issue.
I read many forums and thought I might need to upgrade the OS. Checked in my options and it's indeed platform 5! But the thing is, I can't connect to the Desktop Software. The first time I got an error message 509 on my BB screen saying something like "uncaught exception net_rim_bb_appworld_usb". Looked for a solution online & decided to remove App world. It didn't change much as now my BB just keeps on freezing as soon as it's on USB. Therefore any OS upgrade just seems impossible at the moment.
The only case when my phone seems to 'work' fine is when I start it on safe mode.

Has this ever happened to anyone? Any idea of how I could fix this?

Thanks for your help!

Welcome to CrackBerry! I suggest you do a complete backup using bbdm and do selective restore once your new OS loaded.

Hello Zocster,

That was actually my intention but my phone completely freezes before it manages to get connected to BBDM :(. Can you do a backup + installing the new OS while in safe mode? The only time it doesn 't freeze or turn off is when I start the phone in safe mode so, that would be great...

I finally managed to backup everything. But DDBM doesn't find any new update for my OS. My network provider seems to get stuck with OS 5!

Thought I'd add this info as I just noticed this and in case this could be a hint about the actual problem: I would do a battery pull and once my phone turns on, there would be new emails. I would delete some, mark as read other ones and the phone responds so everything seems fine. Then my phone would do the usual freeze/turn off and when I would do another battery pull to restart it, the same emails I deleted/marked as read show up as new emails again...

Go to plane mode first, All connectivity off. Then batt pull.

Thanks but in the meantime, I actually managed to upgrade the OS yaaay! My phone has been on for about 10min now, which is totally a record since yesterday haha! If it can stay on for at least 30min, I guess my problem is fixed :) *fingers crossed*