PC Bootup problem

This PC is a Intel with win98. I cant get it started up. When i push the power button it starts up then i turn it off and unplug it to put the case back on and it doesnt start up anymore. After fidling around with the power button wire i got it to turn on again. Then i turned it off unplugged and replugged it and i wouldnt start. Please help.

Would tend to suggest maybe the wire is broken inside the sheath or a connection is loose. Could also be a short or a faulty PSU. Try the approach of elimination, find another case/power button and connections, plug that into the jack and see how it goes, if no luck try another PSU. How old is the Unit?

The unit is 5, 6 years old. The powe buton cable connection part is cracked in 3 pieces. But it still worked before.