Motherboard short-circuit with case if all the standoffs are installed

[Reversed]

Hi everyone,

I'm having a rather bizarre problem with my new build. It appears that I have to leave out one of the four (mini-itx) motherboard standoffs otherwise my pc won't POST. The DRAM led will light up and the mobo will reboot within a second or two.

I've tested the DDR3 itself in another computer with memtest and there are no problems with the sticks as far as I know. Removing the motherboard from the case will completely solve the problem, and even removing just the bottom right standoff makes the computer boot, although not very stable.😕

So far I've reseated the cpu, updated the BIOS and tried all combinations of memory modules. The problem does not occur when there is only 1 module in the motherboard. I was hoping some more experienced builders might tell me what the problem could be or tell me what I'm missing.

I can add pictures if they would be of use.

Thanks in advance.

Hardware used:
Asus Z97-i Plus Mini-ITX
i5 4690k
Design Node 304
Cooler Master G550M
Scythe Mugen 4
Corsair Vengeance LP 2x4GB DDR3
GTX 670 EVGA FTW
Crucial MX100 256GB

 

[mfenn]

It'd probably be helpful if you took a picture and annotated it with the standoff locations that are causing problems.

Also, is it the standoffs themselves that are causing problems, or do you have to actually screw the motherboard down to the standoff for the problem to manifest?

 

[corkyg]

Sometimes it pays to use fiber washers under all screwheads.

 

[Micrornd]

Probably a redundant question but -

You are only putting standoffs in the places where the motherboard has a hole for a screw and nowhere else, correct?

 

[SKORPI0]

4 holes, maybe a washer would help in your situation.

 

[Reversed]

Thanks for the replies. The problem occurs with and without the screw in the standoff mfenn. And yes the standoffs are only located in the 4 spots. I will try to buy some washers tomorrow and see where that'll get me.

The CPU cooler requires a backplate, I was wondering if that could have something to do with it as well?

 

[Micrornd]

Lay a thin piece of cardboard (cut to fit between the standoffs) under the MB before putting it in the case.
Watch the thickness, that it doesn't distort the MB.

If that solves the problem, you have your answer.

 

[piasabird]

Maybe the motherboard is defective. Consider sending it back or look for other sites about that motherboard. For instance are they reselling it a lot on E-bay? Are you absolutely certain nothing is touching the back of the motherboard? Maybe it is a problem with the CPU COOLER making contact with the circuits.

Might be time to test the MB outside of the case.

 

[Reversed]

Great idea micrornd, I will try that as well! The mobo works perfectly outside the case piasabird, so I don't think the motherboard is defective.

 

[mfenn]

Thanks for the replies. The problem occurs with and without the screw in the standoff mfenn. And yes the standoffs are only located in the 4 spots. I will try to buy some washers tomorrow and see where that'll get me.

The CPU cooler requires a backplate, I was wondering if that could have something to do with it as well?

So the board works with the cooler backplate installed, but outside of the case?

Do the standoffs appear to line up properly? You're not having to distort the board or anything to get it to line up, are you?

Any other protrusions in the motherboard tray?

If you have to use a washer to make the board power up while it's in the case, then either the board is defective, or you're doing something wrong that I'm not grasping yet. Those little bumps of solder around the screw hole are meant to be electrically connected to the case by the screw and the standoffs.

 

[MongGrel]

Something just sounds odd to me here myself, like the board distorting and bending like you all ready stated.

The whole cardboard thing I'd never heard of...

Most cards are meant to radiate heat a bit, especially Asus I wouldn't mount one that way and use it over time.

 

[PhIlLy ChEeSe]

All screws should only be finger tight, something is a miss. Never heard where you have to leave them out, but I have heard the board wont boot because your not grounded.
If you over tightened the other three, I could see this happening.

 

[Reversed]

So the board works with the cooler backplate installed, but outside of the case?

Yes.

Do the standoffs appear to line up properly? You're not having to distort the board or anything to get it to line up, are you?

No they screw in just fine.

Any other protrusions in the motherboard tray?

Not as far as I know. There is a M.2 SSD slot on the back of the board though, but I don't think it's touching the case.

The screws are definitely not to tight, I've even tried leaving out another standoff, but just having the bottom-right one (on the picture) in the case will result in the problem. I'm starting to think the board is just defective in a weird way..

 

[bruceb]

If you have a digital multimeter, set it to Ohms (low range) disconnect power to the computer. Put one lead on the Chassis. Take the other lead one by one to all the motherboard screws. If you have continuity, then one or more of them is touching the standoff. Then, one screw at a time, remove them until you lose the continuity. That will tell you which standoff is causing your problem.

 

[Puffnstuff]

Have you checked the backplane to see if anything is protruding up that would make contact with the back of the board when it is in the case? Can you please show us a picture of your blackplane without the board in place?

 

[corkyg]

Snother easy fix would be to use nylon or plastic standoffs instead of metal.

 

[mfenn]

If you have a digital multimeter, set it to Ohms (low range) disconnect power to the computer. Put one lead on the Chassis. Take the other lead one by one to all the motherboard screws. If you have continuity, then one or more of them is touching the standoff. Then, one screw at a time, remove them until you lose the continuity. That will tell you which standoff is causing your problem.

The screws on the chassis *should* have continuity to the chassis. They are screwed into standoffs which are screwed into the case after all.

 

[mfenn]

The screws are definitely not to tight, I've even tried leaving out another standoff, but just having the bottom-right one (on the picture) in the case will result in the problem. I'm starting to think the board is just defective in a weird way..

Sure seems that way. If you have some alligator clips (or just a length of wire would work in a pinch), you could try setting the motherboard outside of the case and hooking each screw hole to the case in sequence until you find the problem. Though it's not really clear what you would *do* with that information other than RMA the board anyway.

 

[Micrornd]

The whole cardboard thing I'd never heard of...

Most cards are meant to radiate heat a bit, especially Asus I wouldn't mount one that way and use it over time.

It's just a quick way to see if something on the bottom of the MB is coming into contact with the case and causing the problem.

It acts as an insulator and the cardboard will show impressions and depressions, where something is trying to contact the case.

It is not intended to be permanent as the MB needs some airflow under it to cool it.
It's just a cheap, quick and dirty diagnostic tool to show or eliminate projections from the bottom of the MB as the cause of his problems. 😉

 

[boomerang]

I'm betting the backplate is touching the case. Take the thin cardboard back off of a pad of paper and lay it behind that backplate. Screw it all down and give it a whirl. Another option of course would be to remove that backplate and install the stock cooler as a test. I'm thinking you probably ordered a bare processor though.

 

[Reversed]

I will try the cardboard tonight. I do have a stock cooler laying around but would obviously prefer the other one. The last couple of days I have just one DIMM installed and it works perfectly.. Might be a defective dimm-slot as well.

 

[silicon]

if there is nothing shorting that you can and it sounds like have checked very thoroughly then the board may have a trace or 2 shorting to that particular standoff hole and then to ground when the standoff is sued.if that the case then the board will need to be RMA'd.

 

[boomerang]

I will try the cardboard tonight. I do have a stock cooler laying around but would obviously prefer the other one. The last couple of days I have just one DIMM installed and it works perfectly.. Might be a defective dimm-slot as well.

I suggested the stock cooler as a test.

There doesn't appear to be any way to observe behind the installed motherboard to check for clearance with that case. The cardboard will have an imprint on it if there are clearance issues. The thinner the better.

If I understood earlier posts it works outside of the case with both slots filled. Maybe I've misunderstood. If the opposite is true, I would think you have found your problem without going through anymore troubleshooting. Or perhaps a problem that warrants an RMA.

My reasoning is thus. Small case, short standoffs, with a CPU cooler that requires a backplate. If the panel the motherboard mounts to is not totally flat, you could have contact between the backplate and the case.

I have stuffed contacts on I/O plates into ports on multiple installs and removals while troubleshooting and missed it before. That is another thing to be aware of.

 

[mfenn]

I suggested the stock cooler as a test.

There doesn't appear to be any way to observe behind the installed motherboard to check for clearance with that case. The cardboard will have an imprint on it if there are clearance issues. The thinner the better.

If I understood earlier posts it works outside of the case with both slots filled. Maybe I've misunderstood. If the opposite is true, I would think you have found your problem without going through anymore troubleshooting. Or perhaps a problem that warrants an RMA.

My reasoning is thus. Small case, short standoffs, with a CPU cooler that requires a backplate. If the panel the motherboard mounts to is not totally flat, you could have contact between the backplate and the case.

I have stuffed contacts on I/O plates into ports on multiple installs and removals while troubleshooting and missed it before. That is another thing to be aware of.

:thumbsup::thumbsup: Great advice.

 

[JackMDS]

I usually use Gaffer's* tape.

Put a small piece on each standoffs and few strips of it on the case's metal under the cooler if it has a back plate or metal screws are use there.

Then I expose one stand put a screw and try. If it works OK, I take another piece of the tape and repeat. If one stand creates the problem I leave it insulate with the tape and done. If there is no special considerations the Mobo will be well without one or two screws.

*Gaffer Tape is widely use in the Morie/TV to keep thing down It is good installation water resistant, hold strong but easily peeled off when it is Not needed any more, and it does not leave glue residue when removed.

http://www.amazon.com/ProTapes-Pro-G...6BPZEN8TZMTK63



😎