Chosen Solution
have repaired screen, put in DFU, installed itunes but now iphone wont recognise SIM. iphone is in uk, have tried o2 and 3 but no luck. what to do? have cleaned and checked SIM tray/pins. phone innards cleaned with isopropyl alcohol-can’t find obvious damage to motherboard. Update after much taking apart, cleaning, reseating all connectors-tried cleaning sim tray and easing pins up- reassemble and hey presto! working iphone. thanks lots and lots.
thats hard to tell - there are surely ways to re-wire the complete card reader - but that should be the last option and you can only do that with very scecific tools. i would check the contacts again, if one of them is slightly bent - it could be enough to let the phone not recognize the sim card
