Motherboard problem!

[HobbesMRH]

I just bought an Asus A7N288-VM motherboard and when I try to power it on my power supply just makes a quiet high pitched whining noise, and nothing spins. WHen I connect it to another mobo I have, everything works grand, though I can't get anything to boot or get picture on that motherboard.

The CPU fits nicely into the other mobo, but it's hard to get it into this one. Maybe that would effect the power supply?

[HobbesMRH]

up

[Bovon]

Is the Asus A7N288-VM motherboard new?
Where does the high pitched whining noise seem to come from?
If nothing spins, it must be the power supply is not plugged in good...the 115 - 230 volt switch on the back is in the 230 position and if you live in the US it should be in the 115 volt position.... you may have shorted the motherboard out someway in the case...the best way to begin a new build it to place the motherboard on a cardboard box or large book outside of the case,,install the ram, CPU heatsink and fan, video card and power supply..turn it on by shorting the two pins where the case switch normally connects to the motherboard..No keyboard or anything else is needed.

If you have video and POST..then *carefully* mount the motherboard in the case.

[HobbesMRH]

They were both brand new, I was very careful when installing them and only used demagnetized tools and made sure I was grounded as best I could be. It should also be noted that some of the CPU pins were a bit bent, and it was hard to get it into the Asus board.

[Bovon]

No matter how careful you are, mounting a board in a case can be easily shorted...especially with todays assembly line manufactured cases. Many times the case will have ready made, stamped out..drilled and tapped standoff brackets where you screw the motherboard to the back plate. The surface area of this type of standoff has been found to be too large in diameter and will touch nearby circuit traces, then when a screw is inserted..that trace gets grounded thru that screw.

Remove the motherboard, remove everything..reseat the RAM module once the motherboard is out of the case and laying flat down on a solid surface..mash the ram, down in the socket until the side latches..latch themselves..do not help.

What do you mean the CPU had bent pins?..did you straighten them? If you did not straighten the pins, you certainly should have. Remove the CPU and view the pins carefully, straighten any bent pins up straight..look at others nearby to check alignment. You can straighten those pins by very carefully using a small screwdriver or a blade from a small pocket knife and carefully bend them back up again.

Install the video card, connect a monitor...plug in the power supply and turn it on by shorting those two pins where the case switch normally plugs in.

After this test, come back and tell us what happened.

[HobbesMRH]

How do I short the pins?

[Bovon]

The case on/off switch acts just like a horn button, or doorbell switch. Mash it and the horn blows or the doorbell rings. Release the switch and it stops.

To simulate this when the motherboard is being tested outside of the case where the wires might not stretch that far...simply take a small metal object like a small screwdriver or pen knife blade etc. anything small and metal... place the knife or screwdriver between the two pins just until the fans start up, and then remove the short (knife or screwdriver between the pins). This is what the case switch does.

I have an ATX power supply I use to test run motherboards with. I added a doorbell switch to the metal case of the powersupply..the two wires with the little plug-in's on them came from an old AT case..and when I set up a board to test, I have all I need right there. But...before I did this.. I turned on quite a few power supplies with whatever metal object I had nearby that was small...usually a small screwdriver or my pocket knife.

[HobbesMRH]

I took the screws out of the case and now it's getting power. However, it won't turn on when I press the power button. It did when I shorted it like you had mentioned.

[jmichna]

Originally posted by HobbesMRH
I took the screws out of the case and now it's getting power. However, it won't turn on when I press the power button. It did when I shorted it like you had mentioned.

Double check the power button? I had one occasion where the case bezel was slightly ajar, and it caused the power button to mechanically bind. The switch did't work right until the case front bezel was removed and reinstalled.

[HobbesMRH]

Power button works fine. It works on my other mobo that wont boot or post.