Computer won't turn on, no lights, black screen

[HannibalLecter12]

Hi! I have a problem - my computer won't turn on and it shows a black screen all the time. It does not show any blinking lights at the front side, nothing. The only things that turns on when I press the power button are DVD RW and cooler. The computer is a little older, but still was functional until recently.

Configuration:
Zeus motherboard (I can't find the series number)
Processor Intel Celeron e3300 2.5 GHz
RAM 3x512 DDR2
Graphic card Leadtek Winfast px9500gt 1 GB 128bit DDR2

Please help!

[Geek-9pm]

Do any sound come out of the on board tPC speaker?
Do the keyboards lights come on? Can you use caps lock?
The mouse? Does it light up? (If it is an optical mouse.)
What fans come on?

[Allan]

Sounds like the power supply

[Lorraine walsh]

Have you you sure your monitor is on and working correctly? have you tried plugging another device in to make sure the issue is not your monitor?

[Allan]

Have you you sure your monitor is on and working correctly? have you tried plugging another device in to make sure the issue is not your monitor?

OP says the lights on the computer do not come on either

[HannibalLecter12]

Do any sound come out of the on board tPC speaker?
Do the keyboards lights come on? Can you use caps lock?
The mouse? Does it light up? (If it is an optical mouse.)
What fans come on?

No sound, nothing, no lights on keyboard or mouse. The only fan working is the fan on graphic card.

[patio]

Borrow a known good PSU of the same or greater wattage and swap it in there...you'll know right away if that's the issue.

[HannibalLecter12]

Borrow a known good PSU of the same or greater wattage and swap it in there...you'll know right away if that's the issue.

I just tried my PSU on other computer, it worked perfectly. Maybe it's the motherboard?

[patio]

Maybe