Hi, I'm hoping someone can help me. The other night my husband vacuumed out the dust inside my computer and after hooking everything back up and turning on the CPU, the screen remained blank on the monitor. The orange power light was on, but never turned green like it does normally.

I have an HP Media Center computer, with Windows XP. The machine does start, the fan runs, and it sounds normal to us(no beeps, no weird noises-I don't remember hearing any beeps upon startup before).

We have tried the following solutions:

Hooked up the monitor to my husband's laptop, the monitor worked;
Reseated the video card;
Checked for loose connections or missing pieces;
Rechecked the monitor connection;
Cycled the computer power by completely unplugging it and holding the power button for five seconds then plugging it back in;
Taken out the CMOS battery and put it back in;
Replaced the video card with a new one, albeit it was one that had not been checked by us on another system as we have no other system to use to check it(the old video card was an AGP, the new one is a PCI, we tried that in case it was the AGP slot that was damaged);
Taken the video card out of the slot while the machine was on, checking to see if it beeped(that was suggested as a way to test the motherboard at this or another site).

My husband right now is taking the computer tower to test it with another monitor to see if that works. We can't think of anything else to do short of taking it to be serviced, and we were hoping to avoid that cost. If anyone here can help me that would be great. I'd really appreciate any tips, hints, or advice.

Thanks!

ahhrrrrggg...cringe, vaccum cleaners create more static electricity than a rave party on shagpile!!
This static electricity has the ability to 'fry' any electronic chips and circutry in your computer instantly.

Hard to say if your husband has sent your motherboard or cpu to computer heaven or not, but it dont sound good.
Can you tell us more on exactly what was done?

Used the vacum to remove the layers and layers of dust from inside.

Have done it before, with same computer.

When turn on the computer, lights on front do come on, both fans are running, can hear the hard drive running/thinking/operting.. whatever.

Have not noticed anything missing from the motherboard or anywhere else. Have checked the wires, none are loose.

Noy sure what else to say that hasn't been said yet.

Digitallocksmith is right - most plastic flexible tubes will pick up lots of static. Touching a chip with that may kill it. Better use compressed air in cans to blow the dust away. AFAIK pulling cards and sticking them back in a running computer is not that good either and doesn't make sense - this won't make your computer beep. It just silently crashes.

But what puzzles me now is why your board is not beeping. Try this: Remove all memory modules. Start the computer. Now it definitely should beep. If it doesn't, the tiny loudspeaker is not properly connected or simply absent. Or the BIOS knows a kind of "Silent Boot" option, which is enabled. This option is a bad thing if video fails.

This is all I could think of now, you did already all logical troubleshooting steps. But they are useless if your mainboard doesn't give you the POST beeps.

Since my problem was the same, I thought it'd be better to continue from here....

I, too, unknowingly vacuumed the dust from the fan grates and other vented areas outside the CPU.... but my "no signal to
monitor" problem started before I vacuumed! I pulled the CPU out to check the connections... it was straight outta an old western.... Tumbleweeds of dust blowing by....

When I vacuumed and plugged evrything back in, and started it up, I got the beeps and the whirs, but no monitor signal. What should i do?

The PC may be fried but I have and still do clean all my PC (22) with the blower of a vacuum cleaner and have not fried one yet. Vacuuming might be a major different kettle of fish.
One thing you can try (but would normally produce beeps when booting) is the RAM, he could have knocked it when cleaning. Remove the RAM, one or two chips, clean the contacts with a pencil eraser (Do not touch contacts with fingers) replace, ensuring that they are seated correctly, and try again.