please,need your help with OT301

[looker]

Hi,<br />please I need your help.<br />I have three OT301: first one normaly switch on and catch network,but when I trying to make a call,after a few seconds (1-3s) phone restarting (switch off and start again with no pin request)and cath network ok.<br />second one very often cant switch on(only short beep and lights flesh-nothing on display) sometimes phone switch on corectly,but when I schitched it off,there is no last logo(fast shut down).<br />third one always cant to switch on, there is short light flash sometimes,but this one I can to use to repair other two phones.<br />So have U any idea???<br />What I should to test first?<br />Thank for all replyes and ideas very much.

[nnarta]

Hi!<br />Rehot CPU and everything will be OK! 99%!<br />I meet such ptoblem 3-4 times a week...