2 days b4 I plugged in my friends Nokia phone to my laptop for charging. I used sleep and charge. When I resumed system there was a message box telling "current exceeded in usb ports....". I pressed the reset buton in that window. After sometime while I was doin something it shutdown automatically without any error messages and it was switchig on automatically but aftet the bios screen it go blank and switches off and again try to switch on. I ve to remove the batery to stop this. Sometimes it ll not switch on. If luck favours I am able to startup my laptop and it ll run fir some time and again it will shutdown. Please help me troubleshooting this issue.