E74: There is high chance it's a scaler chip problem (the "ANA" or "HANA" chip near the AV cable connection) it can also be caused by a faulty AV cable so check that first. In some cases it is a problem with the GPU and may be repairable by doing the x-clamp replacement (see error 0102)
Send it to MS if it's in the 1 year generally warranty they will fix it if not they will charge you a fee.