My mobile sony ericsoon W850i no open only flash

I think that your sony ericcson has been dropped somewhere or it is water damaged, if its a white screen which keeps flashing then its overheated or water damaged, it may need a new battery or will be about £30 GBP to fix. If this helps then please vote me!

Thanks

What you have to do is take it to the place that sold it you, and they will repair it for free as long as its not water damage. Mine did this too, they took it away for a week and then sent it back free of charge. (i took mine to carphone warehouse).
hope this helps.