aluminium case shorting mobo or what?

[johntavares]

When I turn power on there is a popping noise and smell of burnt before shutdown. Nothing seems to die for good though and it keeps restarting until I turn power off. But if somebody can figure out what's from just from this vague description, I'd appreciate it. Intuitively it seems like a short circuit situation... I guess otherwise it wouldn't start at all if psu or mobo was broken?

 

[Ketchup]

If you can, set up the basics outside the case (board, cpu, ram, ps, vc) and see what happens when you turn it on. There could be a short that is actually inside the power supply.

 

[denis280]

If you can, set up the basics outside the case (board, cpu, ram, ps, vc) and see what happens when you turn it on. There could be a short that is actually inside the power supply.

+1 got my vote

 

[phasseshifter]

smell burnt..oh not again !!! but yes set it up outside the case .pop hmmmm u did use stand off`s to start with..if you just sat the board on the aluminium well your mobo is prolly toast..aside from anything else time will tell..

check your mobo stand-offs in the case do you have the correct placement of them to match the screw holes in the mobo..and no extra ones......dae ja vue.......

 

[VirtualLarry]

Check the mobo power connectors for melting or discoloration. Both the main ATX 24-pin and the AUX ATX12V.

 

[johntavares]

it's the brass screws between case and mobo missing, didnt realize as neither mobo or case came with ones. the antec ones don't fit lian li though, shouldn't these be standard things? i mean it cross my mind that screwing it directly to aluminium case could have some problem, but nevertheless thought those mobo screw holes wouldnt cause a short.

booted outside the case, though gives "no bootable device" screen, which it gave once when not sparking, seems luckily enough that i didn't kill it totally, gotta just boot with cd drive... but cpu cooler fan freezes for one sec after starting and then the boot continues normally, i dont know if thats normal or something wrong there.

any comments? (besides justifiably calling me stupid)

 

[phasseshifter]

ok so if you can get it to read off a cd rom things might not be totally bad..
u need to get the standoffs for the mobo to mount it..pls list system components make and model pls
is it making pop`s and sparking..i cannot tell exactly from your description

 

[johntavares]

it works, installed linux. i consider my self lucky never having broken anything until this day.
only thing bothering is that "double start" i described. and the setup is: dh67cf, g1620, hx620w.

let the hunt for those non-standard standoffs begin... just explain why pieces of metal between mobo and case prevent a short and screw directly doesn't? or is it because something in the back of mobo is hitting the walls, which i think isn't possible because the inbuilt standoffs should be far enough from case panel (pic below)?

https://doityourselfhtpc.files.wordpress.com/2010/08/p10808645b50255d.jpg

 

[phasseshifter]

ok can you find a way for your mobo to allign properly with those 4 stand offs that are on the plae

 

[phasseshifter]

the double start i usually have seen with gigabyte..it may be some setting needs adjusting in your advanced cpu/ram settings..this may be the reason and also if overclocked this may occur with unacceptable settings

 

[johntavares]

checked, nothing outside the four mobo connect points is touching case panel, so it isn't about the brass standoffs then, but some other random hazardous shorting path?

 

[phasseshifter]

you will notice the stand offs are off set the board only goes one way..
If you have the board secured correctly then there should be no problem`s..
aside from this ..a lot of mobo`s do do a quick shut down it is not liking your bios settings and it resets to a working state
even if you have some setting`s incorrect it will not change them in the bios...
but you will have to check you system cpu clock settings..this seems to me to be the reason

 

[johntavares]

i dont understand... if my board doesn't touch the case from it's back in other points than the four attaching points, i don't need to find extra brass ones? as you see in the pic posted, the case integrated standoffs are high enough.

so it must be something in front touching with case causing the short?
if the double boot isn't harmful, i'll deal with it and try fixing later.

 

[phasseshifter]

yes if you have the board on the correct way it should not be a problem there
look for connectors that may be shorting to the case some where
and no i dont think the double boot is harmful.. do you still have sparks flying..best method.

take the unit to a pitch black room and power it up you will see the ark it should be visible..is it still popping..it may be the supply is faulty..ponders...??

 

[inachu]

I hate those beautiful cases that has raised case risers so you do not need to use the copper ones.

They should just keep things standard.

 

[Ketchup]

Congrats johntavares, on making it this far! So this is a Lian-Li case? Probably the best thing to do would be to send an email to Lian-Li and ask them what you need for this.

As far as why you need them:

Most cases use threaded brass standoffs (Jack Screw Standoffs) for attaching the motherboard to the case chassis. Sometimes threaded or snap-lock plastic standoffs are used, which are less secure, but equally useful in a stationary computer. The standoff provides a margin of space between the motherboard and the case to keep the multiple solder points below from grounding and short-circuiting.

http://en.wikipedia.org/wiki/Computer_case_screws

 

[johntavares]

As far as why you need them:

why you're giving me a lecture about case screws when we just got to the conclusion that the short is not caused from them (or lack of them)?

 

[silicon]

If you can, set up the basics outside the case (board, cpu, ram, ps, vc) and see what happens when you turn it on. There could be a short that is actually inside the power supply.

this. set up outside the case and check for problems. something shorted when in the case and maybe if you examine the board there may be a burned spot obvious. or it may be a faulty power supply with an internal problem. try a different supply id possible.

 

[inachu]

I remember shorting out a custom build server and the lead IT manager demanded to use the current pc cases for the motherboards.

Confirm with another IT tech that the case was too tight of a fit for the motherboard.

So with the above story I learned I ask then is your motherboard a pretty tight fit?

If so then it is more than likely being shorted out.

 

[Ketchup]

why you're giving me a lecture about case screws when we just got to the conclusion that the short is not caused from them (or lack of them)?

Sure. This excerpt from your post here would be the answer:

just explain why pieces of metal between mobo and case prevent a short and screw directly doesn't?