I have a HP media center m7360n , with a 920 intel pentium D processor. I changed the video card which required a more powerful power supply. I upgraded the ram and changed the power supply out to be compatible with the video card. Now i can not get it to turn on. I can watch power hit three different power supplys i have tried but the puter will not turn on or boot up. Any ideas?

after doing this if the power supply fan turns on means your power supply if working fine and if it doesnt work there is problem with power supply.
if the fan turns on and still there is no power there is problem with mother board

Hi. After looking at the specs of your tower, the Celeron cpu you have runs at a slow 533 MHz FSB speed and is a single core processor. The good news is that your motherboard is designed to handle an intel Pentium D Dual Core CPU 900 series. Your motherboard uses a type Socket T plug (CPU Plug type). The processors name is The Pentium D 920. Have Fun.

how did you know that the problem is with video card and not with display. connect the laptop with external monitor or tv if works ok you have problem with display or cable that connect the display with motherboard

Its a slot distribution both 2.0 and 2.1. 2.1 is a bit faster as it leads with version. You can install any VGA card that supports it but keep it in your mind that more heavy vga card will require more power. So, you power supply should be heavy and should bear more power for your card as well as your system.
Sometimes, it require to change the power supply as well.
best of luck!

Graphics support is mainly determine by the mother board. based on the processor you have that mother board should be equipped with a PCI express slot. in that case YES it is Supported. make shure you follow installation instructions and check that you have at least the minimum power supply requirements for the card 380W or above.
Best of luck

does the power supply you bought have a pci express power connector on it to allow the card to receive the correct voltage requirements, as that card is compatible with your system

No, In a store bought PC, the software that runs your computer is closely related to the motherboard and processor that are inside it.

You should purchase a new PC or purchase the parts to build your own PC.

I hope you find this information helpful.

1) Why was the motherboard replaced?

2) If this is in reference to an HP Pavilion Media Center M1070n, it uses an Intel Pentium 4 Model 520 (2.8GHz) processor.

Did you make sure you plugged the 4-pin ATX +12 Volt power cable, into the motherboard?
This is power for a Pentium 4 processor, and on up.

This is HP Support, and the Motherboard Specifications page, for the HP Pavilion Media Center M1070N,

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00208497&tmp_task=prodinfoCategory&lc=en&dlc=en&cc=us&lang=en&product=426501

Scrolling down the page is an illustration, and a photo of the motherboard.

Below the Processor socket is the Northbridge chip.
(The Northbridge chip, and the Southbridge chip are the motherboard chipset)

Intel i915P MCH

In the motherboard photo, and installed in your computer, the Northbridge chip has an aluminum heatsink sitting on top of it. (Has fins on top of the heatsink)

Going across to the Left, from the top left corner of the heatsink, is a square connector with 4 socket holes.
The female connector on the motherboard, for the 4-pin ATX +12 Volt power cable.

4-pin ATX +12 Volt power cable,

http://www.playtool.com/pages/psuconnectors/connectors.html#atx12v4

Two Yellow 12 Volt wires, two Black Ground wires.
Let's start with this, and go from there.

well you may have a bad video card or maybe even a monitor have you tried another monitor? if so, then you can purchase graphics cards at most electronics stores!

Power Supply and Chassis Issues
No boot situations can be caused by any of the following power supply, chassis or fan issues:

• Verify that your chassis and power supply is appropriate for the processor model and frequency and the desktop board you have.
  • An ATX12V or SFX12V with the 2x2 connector is required for all Pentium® 4 processor based and higher Intel® Desktop Boards. Power consumption requirements for high-end video cards, sound cards, peripherals, and the Pentium 4 processor will exceed the typical 5A current capacity of standard ATX & SPX power supplies.
• Do not use 2x2 power cable adapters with non-compatible older power supplies.
• Verify that the power supply has the capacity to power all the devices used in your system.
• Ensure the power cord is firmly connected to the power supply and the AC outlet.
• If the power supply or the AC outlet has an on/off switch, make sure that it is on.
• Determine power supply voltage selector setting (230 volts vs. 115 volts) is correct.
• Check for foreign objects inside the chassis such as screws that may ground the desktop.
• Attach the desktop board correctly to the chassis base with the spacers/stand- offs. Make sure not to tighten the screws too much.
• If possible, use a voltmeter to verify that each output from the power supply is correct. If any output is very low (especially the +5 volt output), consider replacing the power supply.
• If possible, use a voltmeter to verify the PowerGood signal is +5 volts. If the signal is below 1.0 volts, there may be a short or overload causing a constant reset. Consider replacing the power supply.

Ok this may help you to trouble shoot your power supply and it may fix your problems,...I got it from Intel site
http://www.intel.com/support/motherboards/desktop/sb/CS-010254.htm#powersupplyissues

Please let me know if this helped
Thank you, Techlahj