I have a Motorola V550 GSM mobile phone. The keypad lights up but the screen does not. When this first occurred I took out the SIM card and reinserted it and the screen started working normally. This lasted for about a week and once again the screen failed, I tried reinserting the SIM card again, but on this occasion it did not start working again. Could this be a problem with the SIM card or is the problem with the connections to the screen? What can I do to fix my Motorola mobile phone? Please advice. Thanks.