Dell optiplex gx280 device not booting

[mr_whizzy]

i dont really know wats wrong wit this pc i bought. it is a dell optilex gx280 device. it doesnt display @ start up and after a while the cooling fan rolls aT HIGH SPEED but it doesnt display

 

[C12Friedman]

Welcome to Tom's Hardware Forums,
Unfortunately, the description of your problem does not help isolate any particular problem. I'm going to link you to a troubleshooting guide for "new" builds which seems appropriate since there is no set starting point
http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems
Give the guide a shot, more than likely something within will be the issue - post what you find out, even post if you find out nothing helped - it'll be something to work from.
Happy reading/troubleshooting