This might be a stupid question, but basically the logic board of my O2 (UK)-locked iPhone 3GS failed back in August and this iPhone repair shop replaced it. It seemed to be a used logic board since some data from the person who used to own it was still on there, but it was relatively cheap (150 EUR) and everything worked fine, so I didn't care. I received the phone jailbroken and was told that its baseband (05.16.02) was unlockable. Now that iOS 5 has come out, I was considering updating it, but obviously I don't want to lose the ability to unlock the phone since it's the only one I have that works in the UK. By coincidence I checked Cydia at one point and it turns out that ultrasn0w is not installed. I then also realized that the baseband I have is not unlockable by ultrasn0w anyway. So I'm now assuming that the shop either came across a logic board that is simlocked to the O2-UK network or that the logic board does not bear a simlock at all. Is this correct or am I missing something here? And is there a way to check whether the iPhone is simlocked using its serial number? And on a slightly unrelated note - how can I tell which SHSH blobs have been saved? Is it just the first line in Cydia saying "SHSH: iOS 4.1, 4.3.3, 4.3.5"?