iphone 5s error -1 when doing update / restore .upon close inspection of motherboard beside baseband ic u1 rf  component c31_rf missing.according to zxw it appears to be on power line VDDPX_BI AS from u1_rf.16 (in) and appears to go out from u2_rf.66. could this cause error-1 .does anybody have explanation /meaning for VDDPX_BI AS