iPhone 4 restarts, no IMEI, no ECID
4 weeks ago my iPhone started to restart it self quite a few times every day. One day it showed: Can not make or receive calls. Restore needed. Replacing the battery inside the phone did not change the problem.
However restoring didnt not bring any effect. First it got stuck while restoring or restarted itself and iTunes error 1,-1 and 28 came up. When it succeeded to restore it showed me that there would be no sim card installed. I tried to insert 2 different cards and no card without success. The iPhone is factory unlocked so there should be no issue with this.
Furthermore it does not display any IMEI or ECID and I never receives any signal. As far as I could google myself through there could be a problem with the logic board and the baseband. However I do not know how to fix it. I have no warranty on that phone.
I restored 4.3.3 5.0 5.0.1 5.1 5.1.1 all without success (I have SSH Blobs saved).
Is there anyone who can recommmend me anything that could bring me further?