Chosen Solution
Please excuse my inexeperience. Got an Iphone 3gs for my daughter, found that the headphone socket was crackly and the mute/vibrate button not working properly. Changed the ribbon cable, got mute to work, but power button stopped.(headphone still crackling) She then broke screen, replaced this and was working fine but power still not. Many tries at cleaning and aligning seemed to have suceeded, but then got white screen. Tried restoring, but got error 1015. (it was unlocked and jailbroken by others.) Problem is I cant tell whats happening as screen doesnt appear to work. Swapped with working screen from another phone but the same problem. Logic board problem? Help!!
You might want to try recboot and see if you get it out of recovery mode available here, or ireb which is available here since I do not know which OS you are using. It sounds like it is stuck in recovery mode. You may of course have more than one issue, but start with this and see where it takes you and let us know. Good Luck
You probably got a unlocked phone running a custom baseband and you can just restore it in iTunes. You will get an error always. You have to restore to custom firmwares to get it to boot but sounds like you may have caused issues when you tried repairing it.
