My aopen.H500Y.ATX Midi tower.400w psu.problem with on/off butto

Hi,i have a apoen.h500y.atx tower aspire pc.I went to push the on/off button in and it started flashing a blue ring and a little orange light flashing to,it was fast.Aiso my montier keeps saying "No signal",the montier is working ive tried it on a lap top.I after the fast flashing I turn it off unplugged it waited about 60sec and pluded it back in and turned it back on,it did the same flashing.So theres a little pin hole button next to the on/off button,so I pushed it in while computer was still on,i held it in for about 50sec.It turned off then I pushed the on button and it came on(no flashing)just blue ring.Only its still saying no signal and I also have a power dvd version 8.OEM in the tower,i cant open the draw where you would put your dvd.Im not to good with computers so if anyone could help,please.Cheers kind reguards NowizKid