No boot\BIOS screen

[Cobra]

so, upon starting my PC(custom) with windows 7, there is no display, not even the BIOS. i tried to switch the monitor display from the video card(ati radeon 9200se) to the on-board video, thinking that the video card might be dead, but it's the same- no display. i know for a fact that the PC is not even attempting to boot into windows, as i can't do a shutdown by pressing the "power" button the keyboard(which i usually can do, from the user accounts login screen). the lights turn on, and the CD-ROM drives work.

is the power supply fried? how can i go about testing to see what the problem is?

[Allan]

What do you see on the display?

[Cobra]

What do you see on the display?

nothing, the monitor simply says "check video cable". it's essentially the same as when you turn your monitor on, without turning on the PC itself.

[jason2074]

Did it happen just suddenly or any particular event that might have cause this such as while playing games, overheat? If there were activities then you could eliminate first the PSU and reseat or swap the cable/connectors or use another monitor. If PC needs some house cleaning from, you might as well consider doing this.

[Geek-9pm]

You say it is a custom PC. More information is needed to forum members can help you.
Did you build this from parts? When?
Have you built and tested Desktop PCs before?

Wild guess department. A RAM chip failed and stops everything.
Empirical confirmation: When power is applied the keyboard lights flash all on and off and never flash again. No beep from mini-speaker. Those two non-events mean the CPU did not even start the POST. Possible dead CPU, but evil RAM failure* is more indicated, statistically speaking.

* evil RAM failure, when the RAM draws large amount of current  and the PSU can not give proper voltage to the CPU. The RAM is so bad it can not be tested. The PSU is not the issue unless the system was already overloaded because of poor system design. The happens in home-built systems.