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Zero boot capablity, tried to solve: may need new board.

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March 30, 2011 9:58:16 PM

Background:
A few weeks ago my comp had issues starting with flickering lights on boot. Sometimes it didnt boot at all. However, if it was already on, nothing out-of-the-ordinary happened.
i had no idea what was happening, so i just left it and after coming back later, it booted fine. This has happened about three times, and now it has refused to boot for several days.
I tested my PSU using the guidelines on the OCZ forums, and it seems to work.

Current Situation:
However, when everything is plugged in, everything refuses to start. nothing except flickering of power lights.
Even when the computer is off, the power light can flicker, so i leave it unplugged.

If anyone has any ideas about what to try next, I'd love to hear them. Otherwise, I'm looking for a cheap board with these things:

socket LGA 775
1 or 2x PCI-E
(Intel & Nvidia compatability)
must be RAID configurable

I'm willing to buy used, but would definitely require a reputable dealer.

Many Thanks.
a c 110 V Motherboard
March 30, 2011 10:33:28 PM

The symptoms you've described suggest a PSU failure or a short. I'm curious as to what guidelines were followed. If in those guidelines you were instructed to test the P1 connector while it is connected to the mobo and the power is on, then you would be able to use a multimeter to check the voltages on the wires in the P1.

Testing for a case short requires you to breadboard your rig. This is accomplished by removing everything from the case, and rebuilding on a non-conductive surface (such as a phonebook, wood, cardboard, etc). I recommend you breadboard not only to rule out shorts, but to rule out bad front panel circuits as a possible reason for the power issue.

You can find the P1 wire voltages by clicking on the link in my signature.
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a b V Motherboard
March 30, 2011 10:47:20 PM

You cannot test a power supply by just measuring its voltages; substitution is the only test unless you have access to specialized test equipment. The power supply is the most likely cause of your booting problems.
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March 30, 2011 11:03:50 PM

i "tested" my psu with what they called jumping:

Putting a load such as fans on the psu and connecting a green to black wire on the main ATX plug with a paperclip. It did start up.

Thanks for the feedback guys, I don't really know how to test my PSU, but I think I can borrow a voltmeter from someone. Is there a link I link to a test guide you can post?

I may just buy a new one.
Thanks guys
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a c 110 V Motherboard
March 31, 2011 12:38:56 AM

The test you did can result in false positives. You only succeeded in testing one of the two jobs of the PSU. "The paperclip test", as it's known on this forum, only proves that the PSU is converting AC into DC. DC is what all of the components in your system needs. The second job of the PSU is to distribute power where its needed. So, while the jumping the green and black wire shows that the PSU can turn on, it doesn't prove that DC is flowing, or flowing enough, to your system's components.

Testing a seemingly working PSU with a digital multimeter will provied far better results. What you call "the main ATX plug" is the P1 connector. Make sure the P1 connector and the P4 (CPU) connectors are snugly connected to the mobo. Turn the power on. Touch the black lead from the voltmeter to any of the black wires on the back (where the wire is coming out) of the P1 connector. Now, touch the red lead to the following and check your readings against the value next to the color:

Yellow: 12 volts
Red wires: +5 volts
Orange wires: +3.3 volts
Blue wire : -12 volts
Violet wire: 5 volts always on.

Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

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April 1, 2011 12:47:34 AM

Thanks for this, can I test these voltages while the system is off? because its never really "on"
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a c 110 V Motherboard
April 1, 2011 7:22:27 PM

No. If your fans spin, continuously-not just a half revolution- then the power to your mobo is present. However, if you're not getting power to the mobo, then that suggests there is a short somewhere. Try these steps:

1. Disconnect all of the front panel wires (Power, reset, HDD LED, etc)
2. Use a flathead screwdriver, or similar tool, to jump the PWR_SW pins.

Do you see anything other than flickering lights? If so, you've found the problem, if not, bread board your system.

Breadboard 101:

1. Remove everything from the case
2. Place mobo on a non-conductive surface
3. Reinstall CPU/HSF (if it was uninstalled)
4. Reinstall ONE RAM module (see mobo manual for placement)
5. Connect PSU P1 and P4 (remove PSU from case, if need be)
6. Connect monitor to mobo if there is on-board VGA, otherwise reinstall GPU and then connect monitor to GPU
7. Jump the PWR_SW pins

Should your system power up and get a dispaly, you've likely found the problem - there was a short. At this point, test your PSU voltages as previously described just to ensure proper operation.
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April 1, 2011 11:33:31 PM

So, I've disconnected everything except for P1 and P4, jumping the pwr_sw like you said and it tuned on!

So, you say that I've found the problem. This part escapes me, what does this tell me/what is this problem?

I didn't test the voltages yet, b/c I only have access to analog multimeter, I can probably get digital one soon.

Thanks so much for your help so far.
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a c 110 V Motherboard
April 1, 2011 11:43:36 PM

You're not out of the woods yet, but chances are you had a short circuit between your motherboard (or something connected to it) and the case. Connect the monitor to your motherboard or install your GPU, then connect the monitor.

If the system POSTs correctly, you should see a warning on the screen about no boot drive or OS found. If you see this, turn off and install your hard drive. Once the hard drive is in, turn on the system again. If the system boots correctly, you should be able to load into Windows.
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April 2, 2011 12:22:51 AM

So, while you were reading the previous post, I was testing things.

The system will turn on if the P1 and P4 are the only things plugged in, otherwise, stuff like blinking/scary beeps occur.

Does this rule anything out?
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a c 110 V Motherboard
April 2, 2011 1:05:31 AM

Not yet. Just to be sure, while you were testing, did you install just one part at a time? or did you rebuild the whole system?

Your latest post suggests that one of your components are failing. If you want to rule out which one, you'll have to install only one thing at a time, including RAM, individually.

Keep the PSU connected and test the following, one at a time:

1. One RAM stick. Test each DIMM slot.
2. If RAM checks out (no beeps) install your GPU
3. If GPU checks out, (dispaly showing on screen), connect the hard drive

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a b V Motherboard
April 2, 2011 1:17:24 AM

I have reread this thread. The symptoms described are classic for a faulty power supply most telling is this statement

Quote:
The system will turn on if the P1 and P4 are the only things plugged in, otherwise, stuff like blinking/scary beeps occur.


This can only be caused by a faulty power supply.
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April 2, 2011 1:42:26 AM

thanks both, I'm trying to get a loaner PSU to test. Lemme get back to you...
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!