Hp pavilion slimline x3507c pc. when I boot up the monitor remains in standby mode. I have already determined that the problem is in the computer not the monitor. The power supply is good, the fans run, the harddrive is active as well as the dvd burner. My suspicion is either the on board graphics or the motherboard. How do I troubleshoot to determine which is the culprit and fix it.

You probably must change the 'input' or 'source' of the Philips monitor to match the port the HP PC is plugged on. If the monitor is also a TV, it must have a remote with this button, else check the built in buttons.

The screen resolution on the computer is set too high. Log in Safe Mode by pressing the F8 key during boot and lower settings.

If you saying "doesn't always boot", most common would be motherboard...
If your motherboard still beeps, then probably some other components has the problem like RAM, GPU card etc., depends on your motherboard.

Hope that give an idea...

The problems is ether the memory or the video card...
Try to take out the memory then start the computer...

Hi
First,try hooking it up to an external monitor if you have access to one.Unfortunately,we need video to start checking for what may be wrong.
Try the monitor and post back to let me know what happens,and if it shows on the external display we can start looking at potential problems and fixes.
Bob

are you pressing any key to boot from the cd when you get that message??

after windows finishes copying all the installation files during the first stage (dos mode) of the os installation you get a reboot, after the reboot, you should get that message that says press any key to boot from the cd, DON'T PRESS ANY KEY (or you will start again), leave it cd in.. just don't press any key... hopefully the installation process will continue on it's own onto the next stage (graphical mode).

if the computer just goes back to the dos mode without you pressing anything the problem may actually be a real problem and it may require further troubleshooting..

see how that goes with the first suggestion and post back if needed.

good luck

The problem you are encountering is not your monitor but your computer. There is a problem with your CPU unit. To know this info in true then try this.,remove the connections of the monitor from your own computer then use the monitor to the other computer and see. Hope this could help you determine the real problem.

boot into bios and disable standby

Check monitor connections. If this dont work you may need to check into a video card for your machine. It could be the bios but i doubt it and to update that needs to be professional help.
God Bless You

Unplug the AC power, remove the battery, wait a full minute and then reinstall AC and battery. See, if you now power up. Most power up problems are related to AC power, DC input jack, motherboard, memory or processor. A lot depends on your comfort level and expertise in how far you should go in self diagnosis and repair. Good Luck.