Help please, as I am a technophobe (elderly lady) and no idea! I have a Telstra ZTE T816. It worked fine this morning on a local Perth call, then I switched SIM card for a cheaper number to call UK family...and now it won't work at all. Phone is fully charged, it switched on normally with the Telstra logo and "powered by..." but just stays at that. Usually after about 5 seconds it goes pink/orange then the different icons come up. I've tried removing SIM, checking battery etc but each time it is the same - no solution. Any suggestions please?