Hi,

Written brief problem for those who can't be bothered reading essays online, and longer one for those who need more info and background.

Brief Problem:

Sony Ericsson K800i locked to Vodafone network. R1JC002 firmware (generic), CID52. Can only re-flash firmware using XS++ as SeTool2 Lite v1.11 comes up with errors and have re-flashed a few times with K800_R1JC002_MAIN_GENERIC_RED52. Using downloaded or patch generator-created sim_unlock vkp file in SeTool2 comes up with this error: BLOCK @ $44700000 read error. Have only: 00000000 bytes. Tried using Disable DB2020 Security in SeTool2 Lite by just ticking box and then clicking Flash but phone won't turn on afterwards and can only revive phone by using XS++ to flash firmware again. No idea what's wrong or what to do next. Help very much appreciated.

Don't understand much about firmware, GDFS, CID, DB2020, etc. But would like to have it explained please!

Longer Explanation and Background:

I have a Sony Ericsson K800i mobile phone that was bought as a Pay As You Go mobile and is locked to Vodafone.

The phone had been playing up a bit for a while, which seemed software based. Then it just refused to turn on. No white screen flashing up, no blinking red LED from the IR port. Nothing. So, I paid €7 to wotanserver.com to perform an upgrade of the firmware - to R1JC002 - which got the phone working. As I want to start using it on the PAYG O2 network, I thought I'd try performing a network unlock so it'll work with an O2 sim.

I have these software programs: XS++, SeTool2 Lite v1.11 and a VKP unlock patch generator. I have also downloaded firmware files (version R1JC002) from 4shared.com - specifically K800_R1JC002_MAIN_GENERIC_RED52 is the one I'm using.

I've tried a sim unlock vkp file from 4shared.com for my firmware version as well as making my own using the firmware file I have and the patch generator software, and then tried applying them using SeTool2 Lite. Each time it failed saying: BLOCK @ $44700000 read error. Have only: 00000000 bytes.

I still don't understand much about all this, and I don't know what DB2020 security is, but read something about needing to disable it, so I eventually worked out how to try and do that in SeTool2 Lite (ticking the Bypass DB2020 Security box and then clicking Flash button). When doing that, it runs without errors and finishes correctly. Trouble is, the phone is dead afterwards - no white screen flashing, no red LED. Nothing at all, won't switch on. Tried it a few times now but each time it turns phone to a brick and only solution is to flash the firmware again to get the phone working.

I'm now stumped. I don't know what the difference is between firmware, GDFS files and what you are actually backing up when making a GDFS backup - firmware, user files, settings? - and what CID is or does and its relevance to all this. I don't know if the eprom data is separate to the firmware or written during a firmware flash or if it is the firmware. I also don't know what DB2020 means or in what way it affects things and why it needs disabling, or its security needs disabling.

And, of course, I have no idea why the 'remove sim lock' patch isn't working. Although so far I have read that SeTools2 is buggy and doesn't like all phones. I must say that I haven't been able to get it to work with anything; I can't flash firmware with it, it comes up with errors - only XS++ works for that. Unfortunately in XS++ the patching tab doesn't actually work, the button isn't clickable, otherwise I'd like to try that.

Could someone please help me to understand the systems used in these phones, as I could probably help myself a lot once that clicks into place in my mind. It'd also be handy to know why the patch isn't working and why trying to disable DB2020 security is killing the phone. Also knowing what software is best to use would be great.

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Thanks!
James