HP Pavilion a 1020n desktop - green power supply light on back flickers \ pulses when power cord is in place, but system will not respond when the power on button is pressed.

No Power on an HP Pavilion PC Desktop b> Desktop computers are simultaneously more complex and easier than laptops when it comes to troubleshooting. There are more physical components on a desktop, so locating a specific troublesome part can be tricky, but working inside of a desktop computer is straightforward compared to opening and fiddling with a laptop. Power problems are always hardware problems. There are a few simple, preliminary steps to troubleshooting, but power problems often require opening your computer and having a look inside.

The Basics
Unplug everything from your PC except for the power cord. Try turning on the system and look for lights on the front, then on the back. When the power supply is on (receiving power), the small light beneath the plug turns green. If this light doesn't come on, the problem is either connected to the cord or the power supply. Try swapping power cords with the monitor cord to isolate the cord as the source of the problem. Look closely at the voltage selector and make sure it's set appropriately for your country -- 110 in North America and 220 for most other regions. b> The Socket b> Unplug the power cord and switch the voltage selector to the opposite setting. Wait five seconds, then flip it back. This ensures that the switch is engaged. Plug in the power cord again and try turning on the PC. Check the outlet to make sure it's working, and plug your computer direction into the wall socket (remove it from any surge protectors or power bars). Check the power button. If it sticks when you push it, it may not be making contact to engage the system power and will need to be replaced. If the button is going in and out freely, you've done about everything you can do from the outside of the computer. It's time to go inside. b> Open it Up b> Unplug the power cord and hold down the power button for five seconds. This clears all electrical charges from the circuitry and makes it safe to open the computer. Remove the side panel from your system. This process varies a bit from model to model -- some have one or two captive screws on the back of the system, some have an easy release button. Check your manual. b> Power Button b> Locate the power button from the inside and trace the cables to where they plug into the motherboard. Lift up on the connector and then push it firmly back down. Plug the PC back in to its power source and try to power it on. Unplug the computer immediately if the system doesn't power up, and continue troubleshooting. b> Hardware Components b> Disconnect each of the devices in your computer one at a time to locate a faulty piece of hardware. Power cables run from the power supply connect to your optical drive, hard drive, floppy drive (if one exists) and into several places on the system board. This step takes some trial and error detective work and a few minutes: unplug one device, reconnect the power, and try turning on the system. Then disconnect the AC power, plug the device back in and try the next one. If the system powers up at any stage, the device you are unhooking is shorting out the power and needs to be replaced.
http://www.youtube.com/watch?v=HJvYGtbwmh8 To Replace HP Pavilion Desktop Power Supply http://www.youtube.com/watch?v=VcEFUpZSmI4 Hp Pavilion 750n desktop computer basics on this computer b> http://www.youtube.com/watch?v=D8Y2PPMiiB0 HP Pavilion Slimline PSU Upgrade Guide This guide compares the Sparkle SPI270LE - 270 watt PSU against the Shuttle PC50 -300 watt as possible power supply upgrade for a HP Slimline. The s3600t Slimline I used for this video has a Intel Hope this helps.

Could be a number of things wrong with this tower.

-If the computer stays at a black screen with a white cursor, it means it's missing system files and the operating system cannot start up. A reinstall is needed.

-If your computer won't power on, it could be either the power supply or motherboard, or sometimes, both.

-Also, check to see if the RAM is properly inserted into the proper slots.

Hope this was helpful.

May be a bad power supply or power button.

Bad Power supply. Look on the side of your current power supply and find the wattage rating, and buy one of the same rating or higher. Some place like newegg.

Pull the power cord out and press the power button on the PC to drain the power for 10 seconds. Then plug the power cord back in and turn the computer on. If still does not work, then the power supply may be blown out and needs replacement.

Check all wires for loose connections--- if the memory was wrong or something, it would still attempt to boot but stop during the POST and start to beep

You have a bad power supply, easy and cheap to replace

You have a bad power supply. It is not an expensive fix. Remember HP's take HP power supplies. When ordering either look on ebay for your model or order from part supplier.

bad power supply. remove cover, remove power supply and it to best buy and get a new one. easy fix once ya take a look at it

power units not working,, the light means power problem you will need to replace the power supplie