System wont power on unless mb power connector on mb is reset

Remove the side pane to access your motherboard cables, etc. Locate the connector on your motherboard that contains the wires going from your power supply to your motherboard. It will be a large, rectangular connector with a lot of individual wires It is not a ribbon cable but should be located next to a ribbon cable connector and next to a green blinking light on your motherboard (when the power supply is plugged into the wall). Note: This green blinking light is in addition to the green blinking light on the back of the PC.

This next step is important: You have to disconnect the connector noted above from the motherboard WHILE the power suply is plugged into the wall. Wait a few seconds and plug it back in. The blinking reen light on the motherboard should now be a solid green light. The PC should now power up.

If the steps above don't work you will need to get a new power supply.

plug your pc directly to your wall outlet and see if it turns on. If it works, then the problem is your power supply. If power supply has a reset button, press it and try again. If pc does not turn on when plugged to wall outlet, then power supply for pc may be out.

your power supply must be exact and both power connections to the motherboard must be connected. the green light will come on if voltage is supplied but will turn on a low voltage alarm which is a buzzing sound. or it just wont do anything

Here is the link to testing HP power supplies but the blinking light usually means that the power supply is dead.

http://h10025.www1.hp.com/ewfrf/wc/document?docname=bph06788&tmp_task=solveCategory&lc=en&dlc=en&cc=us&lang=en&product=58792

1. Remove All External Devices
2. Check the Computer's Power LED
3. If the power LED has not changed unplug the Power Cable From the Computer Disconnect All Hard Drive Power and Data Cables and power on the computer. If still no go.
4. Remove All PCI, PCI-E, and AGP Expansion Cards .
5. Remove All Memory From the Computer
6. Reseat the ATX and 12-Volt Connections . The ATX connector will be a 4 pin square connector connecting to the motherboard from the power supply and the 12-Volt Connection would be the biggest connector with a lot of colored wires.
7. If still no go.
8. Disconnect the Power Connection to the Chassis Fan
9. If the light still flashes then it could be a power supply or motherboard failure. Try a good know power supply first and if that does not fix the problem it is the motherboard. Also check the back of the tower for 4 lights lables ABCD or 1234.
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posible the PSU has failed or have a short somewhere inside case/MB/hardware

This just happened to my t5026. I had to replace the power supply to fix.

yes it sounds like the power supply is shot, you can get a replacement at any computer shop for around $40. i would put in a 400w or 450w that way if you add another hard drive or opitcal drive it wont be a strain on the new power supply

Good Day,mikeybecerra; TV wont come on mb try these 6 items, please pay attention to the blinking light (it's a code) : 1. Check for no 8.4 volts DC at pin 3 of PC9A10 on the Power PCB, if low or missing replace PC9A10 part # 268P058020. 2. LED does not blink at plug in. Check for 3.3-volts DC at connector RF pin 3 (system reset) if low or missing suspect the reset switch S7L20 part # 432P109010 on the Control PCB. 3. LED does not stop blinking after plug in. Verify the standby supplies, 12-volts at connector KA pin 17, 6-volts at KA pin 18 and the 28-volts at KA pin 19, if the supplies are present suspect the DM PCB part # 934C067001 4. LED does not stop blinking after plug in. Check C9B01, C9B02, C9B10, and C9B11 (1000 UFD 16) on the DM PCB, if they are bad replace them with part # 181P734030 (680 UFD 16 V). LED stops blinking after 70 seconds of plug in but will not power on. 5. LED stops blinking after 70 seconds of plug in but will not power on. Check for 3.2 volts DC at connector RF pin 4 and 5 on the Signal PCB if low suspect problems with the switches/buttons on the Control PCB part # 935D736001 6. LED stops blinking after 70 seconds of plug in but will not power on. Keyboard is not locked and key inputs at connector RF pin 4 and 5 check good suspect the E2P PCB part # 934C061001. Good Luck, big IRISH.

The constant blinking green light means that the TV is not booting up. This is a common problem on this set.You need to remove the shield from the DM board (standing upright on the left where the DTV RF connector is)and inside you will see the four leaky capacitors (1000 MFD 16 VOLT)replace them,plug the TV in and wait 70 seconds for the blinking light to stop,then turn on the TV.The hard part will be removing the board from the TV(lots of screws and connectors,takes time)