Blinking power button

Question

A friend asked me to look at his Gateway DX4640 desktop. When he presses the power button, power goes to the motherboard (NVIDIA nForce 630i MCP73PV, GeForce 7100 chipset) and the CPU fan starts spinning. The power button slowely blinks on and off (blue) and the screen briefly says no signal and then goes black. And nothing else; no post code beeps.

My initial two conjectures were:

1. Vista was stuck in sleep/hibernation mode, or
2. A power off had left the mobo in a bad state.

The fix for both is to:

• Unplug the AC power cord
• hold the power button for 30 second to fully discharge the mobo

It didn't help. I left the system unplugged from AC power for an hour. No change.

I am out of ideas. Has anyone seen anything like this before? What does a blinking blue power button mean? How can I get more data points to guide troubleshooting?

Answer 1

Try re-seating the RAM modules. Sometimes a blinking power light attempts to indicate that one has come loose and the system can't boot properly.

Also, if it's blinking in a specific pattern or sequence (e.g. short-short-long), you might be able to look that up in a manual for the computer or OEM motherboard.

Edit: No luck with any blinking light details in the user and hardware guides for that model, but it's still possible that MSI, or whoever made the motherboard for Gateway, has their own, more detailed guide. Do you see any manufacturer logos or information on the motherboard?

Answer 2

Has anyone done anything inside the case recently - specifically, did someone forget to plug the 12v wires from the power supply back in to the motherboard, or have they somehow worked loose? Or has the power supply simply decided to stop supplying 12v power?

Answer 3

I've seen Dell machines blink the power light when there wasn't enough power to actually power them (happened when one of the phases of our building's power blew out). Some machines worked, but notably the Dell's did not. Yours could be an issue of an insufficient and/or failing power supply

Answer 4

I've seen similar issues if the comp. has had a heat problem. Typically this has come from the computer never having been opened and given a good dusting out (esp. if it's in an enclosed space). Go and get a can of that compressed air, unplug and open up the computer, if it's really dusty take it outside, and use short blasts of air to clear the dust. Make sure to not tilt the can or else you'll get the really, really, cold air and you don't want extreme temps. on your electrical components (plus it leaves moisture, also bad). Once you get the dust out (also blow some through the power supply and drive bays) hook everything back up and see if that helps.

Answer 5

Ensure that all cards/connectors are seated correctly.

Answer 6

Currently, I'm having the same problem with a Gateway DX4640. The customer brought it in stating that the machine said that it found new hardware even though he had not added any peripheral devices to the desktop. I personally broke the warranty seal on the case so I know nothing had been installed internally. When the PC is powered on there is no video signal going to the screen causing it to go in to power save mode. The power light on the tower slowly flashes blue. I've tested the PSU, replaced the PSU, stripped the tower of all components leaving the just the power supply connected and I do get a continuous beeping sound which I would assume is due to lack of memory. During this time there is still no POST. When RAM is put back in it goes back to the same flashing blue light which also happens without RAM except there is then the beeping sound. I've tried swapping RAM, using different memory banks, different PSU, resetting the BIOS, and of course draining the power out of the board. The only thing I have not swapped out is the motherboard and the processor. If someone does figure out how to get the PC out of this sleeping state let us know. If it's not a PC stuck in power save mode then it's probably a bad board.

Answer 7

I had the same prob. with a friends pc. What i did was cleared the cmos. It took a few times for it to clear (approx 6 tries) but then i turned on the pc and it started up. Dont second guess yourself. if the mobo and all other components are getting power then it might not be your psu. every psu that i seen go out did not distribute any power to pc. so trace it back to mobo and start by clearing cmos :)

Answer 8

I'm not sure if pressing the power button for 30 seconds is the documented way to "discharge the mobo" but normally these things have batteries. My experience with an MSI board was to take the battery out, AND short the bios clr (clear) jumper for 10 minutes. Doing it for 5 minutes did not do the trick, it had to be longer for some reason. Note that normally just shorting bios clear will clear the bios, but this board had some manufacturing issues and needed to have the battery removed and the jumper shorted for a while.

Now, if that doesn't help, and I'm betting it won't, unplug everything but the power from the machine, that means the drives and memory too. If you see an onboard piezo buzzer, it should beep at this point when turned on. Plug things in one at a time, starting with the memory (it's okay to put all the memory in at once) and ending with the keyboard. It should beep for a missing keyboard each time.

* 7 years later, someone misread this... UPDATED *
"Unplug everything but the power" is something you do as you would with any change to your computer's components. You unplug the mains power, wait for the PSU to to discharge (your motherboard may have a light for this), ground yourself, modify the components by unplugging everything attached to the motherboard except the power connector, then proceed to test this and each change in isolation by listening for the POST beeps. "Plug things in one at a time" does not mean "Hot plug things". Power down after each step, disconnect the mains power, wait for the discharge, ground yourself, add a component back. The step at which your board does not beep, is the step at which you've added a defective component or found a part of the motherboard that doesn't work as intended.