Help me please

you have conection problem try to change the cabel

Could also be UPP problem

sorry for the question but,
What is a UPP problem?

UPP means cpu, try notice front board there is ic writen UPP.
as for my experience its flash prob try change the flash if cant UEM. normally UPP didnt coz much prob unless no network.

Usually this problem is only the connection between your phone and the cable check both of them..

I think's what Hanukka say is true because sometimes my 8310 shown contact service and if not contact service signal is too low

cable or upp ploblem