[kgiles]

I am having a really irritating problem. I just installed my old MSI motherboard into a new case and I am having problems. It powers on and successfully POSTs when out of the case with only RAM, HDD, CPU, CPU fan, and video however when I put it in the case it will not POST and the fans spin for a few seconds only. At that point I was sure that it was a issue with the mothboard grounding to the case so I put non-conductive insulation all behind the board and put non-conductive washers on the front and back of all the posts holding the board in but still same result. At this point the only thing from the motherboard that is touching the case is the Serial/USB/ect. connectors. I also tried starting it without the video in the case thinking it was something there but same result. Just to make things more interesting, if I unplug the 4 PIN 12V JWR1 connector it powers on, POSTS, and even completly boots up . Its been running for a day or so like this. I also went over the PSU ratings for amperage and it is all suffecient, 420W, 18A +12V, ect I can post the rest from home later if anything thinks that its the PSU not being big enough but the case and the PSU are both brand new. I would try another PSU but I don't have one available, wanted to get some advice before running off to return it. I also tested the voltage of the outputs and they were all within range when not connected.

So I have two questions. First does anyone have any other idea as to what the problem might be?

Second, does anyone have any idea whether I can successfully run without the 4 PIN 12V supply or have any way to test it? Its run like this for 2 days, I installed Windows, drivers, and pretty much everything with no problems. I am just wondering if I will start to have issues under load like when playing a high end game or something. I should add that I checked the motherboard manual and it wasn't completely clear on whether the JWR1 connection was required. It says "Attaching the ATX power supply to the connector help offer sufficient
voltage to Pentium 4 CPU". Doesn't really say its definately required.

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Do you own an ohm meter? Sounds like your 12v is shorted to floating ground on the motherboard. Since you say you isolated the motherboard, I would guess there is actually a trace to ground somewhere... or, the board is bending during mounting and causing an internal short.

You might try fully mounting the board and then removing 1 screw at a time, powering up, then checking to see if the released stress on the board lets it operate.

Or you could tweak (twist) the motherboard ever so slightly outside the case and see if the power will drop out.

There is definitely something getting to ground and probably something to do with the P4/K8 connector (4 pin).

I'm surprised you're able to run without the 4 pin connector. My system coughs!

makai

[makai]

Do you own an ohm meter? Sounds like your 12v is shorted to floating ground on the motherboard. Since you say you isolated the motherboard, I would guess there is actually a trace to ground somewhere... or, the board is bending during mounting and causing an internal short.

You might try fully mounting the board and then removing 1 screw at a time, powering up, then checking to see if the released stress on the board lets it operate.

Or you could tweak (twist) the motherboard ever so slightly outside the case and see if the power will drop out.

There is definitely something getting to ground and probably something to do with the P4/K8 connector (4 pin).

I'm surprised you're able to run without the 4 pin connector. My system coughs!

makai