10-06-2013, 08:11 PM
Don't bother upgrading to iOS7 because as mentioned it won't affect the value since it can be done for free anyway and there are still people who don't want 7 at all and will hang on to iOS6 for as long as possible and given that the phone has already suffered a lot of abuse you probably won't get much for it anyway after disclosing the hardships that befell it to date although that doesn't mean it won't have some value to somebody.
If you connect the phone to iTunes and look in the sidebar on the left you can Ctrl-click on the phone and select Backup from the contextual menu and the only function that will transpire is the backing up of your phones data so no worries about accidentally installing iOS7.
Unless the cable you're using is an Apple cable that you know came from Apple or was the cable included with the phone you might want to try another cable known to function properly because counterfeit cables that look like Apple cables or a faulty genuine Apple cable could be the cause of the popup so it would be a good idea to rule out the simple hardware as opposed to a problem in the phone.
It's too bad you want to keep it at iOS7 although there is good reason to do so as previously mentioned but it's possible that a Restore could clear up the dialog which would be annoying to a potential buyer eventually but that means the Restored software would be iOS7.
One last thing you could try if you haven't done so already is
restarting the phone by holding the Home and Sleep buttons until it restarts because this often fixes various software gothchas without needing more advanced rescue efforts.
If you connect the phone to iTunes and look in the sidebar on the left you can Ctrl-click on the phone and select Backup from the contextual menu and the only function that will transpire is the backing up of your phones data so no worries about accidentally installing iOS7.
Unless the cable you're using is an Apple cable that you know came from Apple or was the cable included with the phone you might want to try another cable known to function properly because counterfeit cables that look like Apple cables or a faulty genuine Apple cable could be the cause of the popup so it would be a good idea to rule out the simple hardware as opposed to a problem in the phone.
It's too bad you want to keep it at iOS7 although there is good reason to do so as previously mentioned but it's possible that a Restore could clear up the dialog which would be annoying to a potential buyer eventually but that means the Restored software would be iOS7.
One last thing you could try if you haven't done so already is
restarting the phone by holding the Home and Sleep buttons until it restarts because this often fixes various software gothchas without needing more advanced rescue efforts.