Mobo shorting with case?

[SavageOne]

Hello AnandTech Community,
I just spray painted the inside of my case black with rustolem spray paint and every time I try to run my computer inside the case it won't start. It works perfectly if I have the motherboard on a book or the table but when I try to run it inside the case I think it shorts out from the spray paint (the heat sink is kinda heavy so it might be touching). I tried to run my computer using the black spungy thing that comes with motherboards between the case and the motherboard and it works just fine. I want to know if it is safe to keep it under the motherboard for a long period of time without it catching on fire or insulating too much heat. Or is there anything else I can use to put between the case and the motherboard. I was also thinking of putting masking tape on the case under the motherboard. I'd appreciate any ideas and opinions anyone has.
Thank You,
A.J.

 

[WoodButcher]

Nip the long points on the backside of the mobo. Nylon washers can be hot glued to the back of the mobo would work also.

 

[SavageOne]

ya maybe i'll glue a loose leaf sized nylon sheet onto the case to prevent any contact. I don't want to do anything to the motherboard and risk damaging it

 

[WoodButcher]

Nipping the points won't hurt the mobo, it is something generally done at the factory. Quite possibly one or more slipped by the inspectors. Small nipper pliers can be had at the hardware store for a couple dollars and you won't need to worry about the points wearing through the sheet you mentioned. Good idea btw.

 

[SavageOne]

Thanks I'll do that, but something weird is also happening now my graphics card won't output anything. I had the tower on its side and put the nylon piece between the mobo and the case and it was running fine, but when I closed the back of case (side window still open) and moved two of the case fans around it won't output anything. It will boot up and stay running but I can't see anything so I have to manually power off. I checked all the wires and reseated the gpu but it still won't output anything no beeps are coming up or anything. Also ususally my computer makes boot beep but now it doesn't. Any Ideas? I think I am just going to pull out the mobo again to see if the nylon sheet is causing any problems.

Edit: The gpu works outside of the case. Dammit I think I am just going to repspray the whole case again and then spray a non conductive gloss coat on top of it. Hopefully gloss coat is non conductive. Thanks for all the help I'll let you know how it turns out.

 

[Zepper]

Where are the standoffs that are supposed to be under the mobo? You'd never have to "trim the trees" if you're using the proper standoffs. Sounds like someone hasn't a clue to me... ;-) Here's a link for noob builders: http://www.mechbgon.com .

.bh.

 

[SavageOne]

I am using the standoffs that came with the motherboard the threaded ones. I might buy longer ones after I respray the case. Thanks for the site Zep, this is my first build from 3 months ago so I don't mind being called a newb not a noob.

 

[WoodButcher]

If you change the length of the standoffs the backplate and PCI slots don't fly, did you possibly put an extra standoff where it shouldn't be?

 

[SavageOne]

I did put some extras but then I realized it might be shorting it, so I removed it and it still wouldn't work. I think there is some spray paint dust still messing with the board. I am going to respray it on friday and add a non conductive clear coat and make sure that I wipe all the dust off better. About the length of the standoffs I am going to try and see if they have any slightly longer then the ones I have, otherwise I am just going to leave it alone.

 

[Jessica69]

Originally posted by: SavageOne
I am using the standoffs that came with the motherboard the threaded ones.

Just a note....standoffs don't come with the motherboard, they come with the case, so the motherboard will have the appropriate height to fit the I/O backplane of the mb through the included I/O panel hole in the case and fit correctly the I/O backplate, included with your mb, when installed in the case.

To me it almost sounds like you've got too much paint on the mb mounting plate in your case, raising it up slightly, almost like using taller standoffs. Also, when you put your screws through your mb into the standoffs and the standoffs are mounted in your case, you've essentially made a grounded connection for the mb......the screwholes on your mb used for mounting it are surrounded with metal.....look at the holes. Even using paper or any other washers under the mb doesn't defeat this grounding, as the screw conducts the grounding from the mb to the standoff....but when painting the mb's mounting plate in your case, you've now insulated the case from the mb, neutralizing the grounding effect.....thereby possibly giving you your problems.

Try scraping off some of the paint around and in the screw holes in the case's mb mounting plate.....may help.

 

[daw123]

Originally posted by: Jessica69

Originally posted by: SavageOne
I am using the standoffs that came with the motherboard the threaded ones.

Just a note....standoffs don't come with the motherboard, they come with the case, so the motherboard will have the appropriate height to fit the I/O backplane of the mb through the included I/O panel hole in the case and fit correctly the I/O backplate, included with your mb, when installed in the case.

To me it almost sounds like you've got too much paint on the mb mounting plate in your case, raising it up slightly, almost like using taller standoffs. Also, when you put your screws through your mb into the standoffs and the standoffs are mounted in your case, you've essentially made a grounded connection for the mb......the screwholes on your mb used for mounting it are surrounded with metal.....look at the holes. Even using paper or any other washers under the mb doesn't defeat this grounding, as the screw conducts the grounding from the mb to the standoff....but when painting the mb's mounting plate in your case, you've now insulated the case from the mb, neutralizing the grounding effect.....thereby possibly giving you your problems.

Try scraping off some of the paint around and in the screw holes in the case's mb mounting plate.....may help.

Good call

 

[SavageOne]

Wow Thanks for the info. I am going to do that when I get home and let you know how it turns out. Ah Thanks for pointing out my mistake that the standoffs come with the motherboard instead of the case. Its been 3 months since I built my machine, so I forgot. On a side note how would I reground the the case? should I connect a wire from the standoffs to the case of the psu? (not gonna try it just wondering).

 

[Jessica69]

Just scrape the paint off where the standoff contacts the case itself.....just around the hole and inside the hole. I used a miniature screwdriver and thin round wire brush to remove the paint from inside the mounting holes on my mb tray after I painted it. After all, no one is going to see underneath your mb, are they?

 

[Zepper]

Yes, the paint is possibly interfering. The mobo is supposed to be grounded thru the standoffs to the mobo tray so if you got paint around where the standoffs screw into the mobo pan and into the standoff screw threads, then parts of the mobo may be floating at a different potential than other parts (though it shouldn't be as all the standoffs are connected to the ground plane in the mobo). So I'd remove the paint from where the standoffs make contact with the mobo pan. I doubt the paint would be thick enough to make the mechanical fit be off enough to make a difference.

If you want to use some of the extra holes in the mobo for extra support, you need to use the old-school nylon standoffs so that nothing is accidentally shorted (I do that all the time around the card and memory slots) - if you have already used metal standoffs where they weren't supposed to be, then it may be too late if something important got shorted to ground. Standoff holes usually have shiny tinned lands (rings) around them large enough to prevent shorting nearby components and to help prevent crushing of the mobo from overtightening.

.bh.

 

[SavageOne]

Thanks for the all the help everybody, scraping the paint off from from the standoff holes got it working again. My computer has been running for 3 hrs now so I think everything is okay now.