My hp pavilian desktop power button won't turn on my computer. How can I fix this problem?

when it is blinking red it means its in sleep mode. at that time the fan is turned off by your computer to save power. Press the power button oce again and u should have it up and running.

it sounds like power supply problem

YOUR MOBO IS FRIED

Indicates you have a bad Power Supply, to me.
Weak voltage power rail.

1) ALL of the LED lights combined use less than 1 Watt of power.
2) EACH fan uses 2 to 3 Watts
3) A typical Processor can use 51 to 125 Watts.
Depends on what Processor it is.

(The Pavilion a6750f uses an ATX power supply, that has a maximum rated wattage of 300 Watts.

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01619697&lc=en&dlc=en&cc=ca&lang=en&product=3872428#N934

The AMD Phenom X4 9650 processor can use up to 95 Watts,

http://en.wikipedia.org/wiki/List_of_AMD_Phenom_microprocessors#.22Agena.22_.28B2_.26_B3.2C_65_nm.2C_quad-core.29

(In the chart under the heading TDP)

Enough power to spin fan's, but not enough to turn the Processor on.
Not enough to also light that Power On LED light.

No Processor operating = No Video Signal from the computer.
Hence the monitor is blank.
(No Signal)

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01356113&tmp_track_link=ot_recdoc/c01619697/en_ca/c01356113/loc:3&lc=en&dlc=en&cc=ca&lang=en&product=3872428

NOTE*
Computer unplugged from power.
Anti-Static Precautions observed.

Anti-Static Precautions:
Your body carries Static electricity.

Static will fry out (Short Circuit) the hardware components inside a computer.
(You may not even see it, or feel it)

Computer unplugged from power, computer case open, working on a table;
TOUCH the metal frame of the open computer case, to relieve your body of Static.
Should you leave your computer in the middle of working on it, upon your return be be SURE to Touch the metal frame again.

the screen might be worn out. or connecots inside the computer could have gone bad. make sure the contrast/brightness settings haven't been changed.

The problem most likely resides within your fan. Try to clean out the inside of the computer with compressed air. Also check to make sure there arnt any obstructions touching the fan such as wires. This should fix your problem.

Gary

You will need to get a USB to parallel cable.

The one year warranty is from HP.
Contact HP -UK tech support for assistance

http://welcome.hp.com/country/uk/en/support.html

How did you test to see if your wall plug had power? Did you at least see the HP logo when you booted up your computer? let me know before I can give you further instructions!

Here's a link to the FIX details