SO nokia c3 firmware downgrade | Phone/Device Issues and Features | Consumer forum

So the nokia c3 is quite a handy little phone if all you need to do is text, the occasional phone call and listen to the FM radio. The problem is that Nokia is sluggish in releasing north american firmware files, and if you're like me you enjoy running the latest and greatest firmware version available from another locale.

Long story short I was using the australian 8.70 firmware and wanted to downgrade to 8.63, the latest available for the original speakout product code (product code 059F4C9). Nokia BB5 SL3 phones don't allow firmware downgrading, i.e. you can flash the device with an older firmware image but it won't boot, a fact which I found myself verifying. But, accidentally, I discovered that I COULD successfully downgrade to the 059F4C9 4.60 version, which was what the phone came with when it was brand new. And from there you can easily upgrade to 8.63. Perhaps there is a safety feature present which always allows loading of the factory original firmware version, regardless of whether or not it is a downgrade.

Just thought I would share since I would have appreciated this information a little earlier.