Fujitsu siemens amilo m-7405 laptop have problem... i connect my mobile with usb port and then suddenly laptop screen appear some linning and and laptop hanged..i restart the laptop and then try to connect any usb devise they cannot recgonized it...and laptop work too much slow..then i decide to reinstall the operating system...while installing the laptop hanged on 34 minutes....then i opend the back cover of the laptop for cheacking because the laptop too mush heats up, the intel 82801DBM chip is heatiing up........i know this chip having LPC and USB controllers..etc.....but can u tell me that is this the problem of southbridge.....!! and can i change this chip ???

thx