Hi all, Need some advice please on my friends pc. Last night he heard a big bang from his fuse box and upon investigating it discovered a fuse had blown...not that strange i hear you say ! but....later he went to turn his pc on and it didnt work. so because he know nothing about them he ask me to look at it for him ( i dont know lots myself, just basic stuff). First thing i checked was the fuse and it was fine, i have a spare PSU so i popped it in and bingo...it works so i guess his just blew although how it blew without been switched on is a mystery (powersurge ???). Anyway i only had a usb keyboard available at the time to plug in to test if the pc itself worked fine and it seemed ok so i took it back to his house and connected it all back up for him only to discover that there is a serious issue now with the USB ports. When i plugged his ps2 mouse and keyboard back in, all was fine so i plugged his usb printer in and again all fine, i then plugged his usb speedtouch modem in and that worked but now the mouse stopped working !!! so i tried the usb port the printer was plugged into although the modem worked again the mouse didnt. This is the same for usb memory sticks, they work but stop the mouse from responding. The only thing that lets the mouse function is the printer, and that dosent care which usb its plugged itnto. So to simplify. psu blew up so i replaced it and tested pc with a usb keboard. Took pc back and plugged in ps2 mouse and keyboard and all works fine, Plug usb printer in and all is fine, plug any other usb device in and the mouse stops functioning even though the usb devise works fine !!! ???? Sorry for the long winded explanation, hope it makes some sence and thank you in advance for any advice. Best regards, Vale.