i recently got a modem for another computerso to install it i removed the case of my machine and inserted the card, it began to boot up for no reason so i removed the power cable and since that it hasn't booted up
If you plug in a card with the power connected (as you clearly did) - then you've probably blown your motherboard.
I had a friend who did this recently, with a sound card. What you need to realise (sorry, it's too late now), is that just a normal power down does not remove power from the motherboard. Only the switch on the power supply, or better still, unplugging the mains cable, can remove all power from the motherboard.
i left the computer completely isolated from the mains at night then plugged it in the next morning as it used to do it began to boot up, but it just sat there not giving out a video signal. could i have by chance erased the info on the bios chip some how? this would explain ist idle state?
first thing is first give your pc some tlc open it up(but take the power out first) and look at all the settings make shure they are all correct still and nothing bad has happened inside leave it disconnected for a day then plug it up again and to be safe as you may well of somhow magaged it i would find the latest BIOS for your board and flash it with the new code.
everyone always seems scared to do flashing but its simple all youve got to do is make absolutely shure you have the correct BIOS for your board.(and thats not hard ppl!!all youve got to do is use common sense and your eyes!) here is a tip though make a note if the .bin file exactly as you seeit otherwise the flash procedure probably wont work it never normally does-saves you having to reboot the pc look at the file and do it again
oh change your cpu voltage to a lower setting and turn it on if it works fine if not put it back to normal the reason for this is that by doing it you can "jolt" your pc back to life-somtimes