text: dead computer, how to tell if it's the motherboard or power supply? my computer made a loud popping noise (like a gunshot), and hasn't worked since.    it won't start.   how to tell if it's the motherboard or power supply that needs replacement? i just went through this.  chances are, if you turn on the power to your computer (not the power strip, duh) and the light is out and it makes no noise what-so-ever, it's the power supply.  these are easy to replace and you can call your computer maker (i.e. dell/gateway/hp, etc.) and get a replacement.  if it's an odd-brand or you don't have the specs, still, pull the darn thing out (taking note of where everything was plugged into) and drag it to a computer store, radio shack, best buy, etc.   you can get a new powersupply for like $30-60 bucks depending on what it is.  take it home, plug it in.  if it don't work, pull it back out and take it back (gee, i'm sorry, my wife bought this for me 'cause she thought it was a cd burner) ... ;-)  power supplies last about 2-4 years ... the best advice that i've given you is to yank it out and take it with you.  power supplies are all different shapes and sizes (a finite number of standard ones), but you don't want to order something off of the internet that has all the same specs and is just 4" too tall to fit into your case !  my money's on your power supply.   btw:  did you check the fuse ?  some older pc's have fuses.  i hope this helps.  don't be intimidated ... things only plug in one way ... when you're done and the cd don't work, open it back up and you'll be like, "duh, i forgot to plug that in."    ;-)  good luck !  p.s. (it's the power supply)