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Power on issues

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  • Homebuilt
  • Power Switch
  • Power
  • Systems
Last response: in Systems
May 5, 2008 12:51:30 AM

I recently built a new system (all new components) and i've run into a strange issue, and not sure where to best ask it, so I figured i'd try here.

When I hit the power switch on my case, often "nothing happens". No beeps, no whirls, no fans, nothing. The MB is getting power from the PSU and its LED is on. Now to make this more perplexing, sometimes after I push the power button, if I walk away, the computer will suddenly come on like 30 minutes later (this is not an exaggeration, i've had it happen at 50 minutes after before).

I have yet to even think of anything that Can explain this behavior, I thought perhaps a loose connector or wire, but there is no real breeze in the area, and the computer was not "bumped" or jostled in any way prior to self starting. I have been in the BIOS and none of the "turn on when XXX" options are enabled.

I have checked the wires that go to the MB and the Case power switch, and there doesn't appear to be any damage or looseness. I have removed the MB convenience connector and made sure the power switch, reset button, Power Led, system speaker, HDD activity LED ect are all plugged in directly to the MB on the correct pins.

I have a Raidmax Smilodon case,
I have an ASUS P5E MG613 (X38 chipset) MB
I have a 610 Watt Silencer (PC & C) PSU

I can't think of any other components other then the MB, Case switches/wires, and PSU that could cause this kind of behavior. Any thoughts or anyone else ever seen this?

More about : power issues

May 5, 2008 12:55:40 AM

I would pull everything out of the case and assemble it on a desktop. Put the MB on something non-conductive like the box/bag that it came in (or a phone book). This will tell you if something is touching where it shouldn't be on the back of the motherboard.
May 5, 2008 12:32:30 PM

The fact that the machine will power on normally, display graphics, post the BIOS, and allow you to enter and configure the BIOS settings leads to me to believe that the hardware is fine, and operating normally, are you getting any messages from the BIOS after it posts that may give us an indication of what is going on?

without more information I would say you have a configuration issue, perhaps boot order, or improperly configured hard drive, or chipset configuration, all these things would cause the problem you are experiancing.

More information would be helpfull such as what type of hard drive you are using, is it PATA or SATA, are you attempting to run raid, if you have onboard raid does it have a 3rd party raid chip or just the x38 intergrated raid, and if so do you have the drive plugged into the correct port, things of that nature.
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May 5, 2008 3:33:04 PM

This may sound silly, but try replacing the power switch. As the system will turn on (eventually) it sounds like a faulty power switch. A test would be to short the pins, using a screwdriver (after removing the connector of course) if it turns on, replace the switch. Some can be found here: http://www.frozencpu.com/cat/l3/g44/c153/s316/list/p1/D...
May 5, 2008 7:55:34 PM

I'm not at home currently (doing that work thing), But I plan to test some more things when I'm home tonight.

I don't think its a configuration issue, I don't see how it can be anything other then a hardware issue (for Xeenrecoil). It doesn't even power up fans and the like, its not just a POST problem. I did get into the BIOS and check all the configuration, and to me it looks good. I had this problem when I first built the system (with the 0203 bios revision) and I flashed the bios to 0607 so that it would properly recognize my C2Q Q9450 processer.

I suspected the switch as a possible problem (for IH8U) but it seems odd that after you press the power switch that it would randomly come on some time between 10 and 50 minutes later (occasionally it works right away). There is no breeze in the room and nothing to physically "bump" the tower so I don't think its a loose wire. I also removed the case front and inspected the wires from end to end to look for any visible issues and didn't see any with just a quick eyeball inspection. I have not tested the wires with a meter yet, nor have I tried swapping out the reset switch for the power switch (I assume they are the same other then what button they connect to).

I will try the shorting trick as well directly on the MB for the power switch when I get home. I left it running overnight (and presumably all day today) to see if I get any unexpected power offs. I've only had the system together for 3 days, so I'm not completely sure as to the frequency of the issue. I'm going to try to get some more data as to how often it occurs.
May 6, 2008 4:56:55 PM

Minor update thus far. I have not been able to get it to exhibit the problem in the last day or so. I turned it off and on several times (Both turning it back on immediately and also letting it sit for 5-10 min and trying). Also I have twice left it powered off for 10+ hours, and it doesn't seem to turn itself on without actually pushing the power button.

Until I get an instance of it not working I can't test the power switch pin theory (shorting the 2 pins with a screwdriver) but I will definitely test this if it fails to boot again. I'm suspecting a flakey MB at this point and I might just RMA it to be sure. At this point I doubt its the switch, and low chance its the PSU (but still remotely possible).