New motherboard problem MSI

I have an ATX running windows XP SP2 and recently my PC had a motherboard problem so I purchased a replacement MSI KT6V, removed my old MSI K7T-266 and re-assembled the PC I thought that I had replaced the various sockets on all the correct pins and before I finished re-assembling, I powered up only to find that after 10-15 seconds it powered down by itself. It would re-start after a minute or so and then do the same again. The mobo came with scant information regarding set up so I expect that maybe a couple of sockets are misplaced. If anyone can provide any guidance, it would be appreciated. For the record, all 3 fans power initially up as do the hard drives

 

I would check the power switch connection. You may have the pins on wrong. If they are on correctly , power on the computer then remove one or both of the wires. If it stays running, then the switch itself probably is sticking.

Sam

 

Thanks for your suggestion, very useful however I am still a bit in the dark about a number of unfamiliar terms as follows:


There are some unfamiliar descriptions in the user manual for the Front panel connectors .
.
JFP1 (LEDs, Switches)
Pin 1, HD_LED_P, Hard Disk LED pull up (what is a pull up?
Does the “P” in "LED_P" indicate “+”?)
.
Pin 2, FPPWR/SLP, MSG LED pull-up(what is a pull up? What's an SLP?)
.
Pin 3, HD_LED_N, hard disk active LED (is this a “+” or “-“?
Does the “N” in "LED_N "indicate “-“?)
.
Pin 4, FPPWR/SLP, MSG LED pull up (what is a pull up?)
.
Pin 5, RST_SW_N, Reset switch low reference pull down to ground (is this a “-“?)
.
Pin 6, PWR_SW_P, Power switch high reference pull up (is this a “-“ or a “+”?)
.
Pin 7, RST_SW_P, Reset switch high reference pull up (you get the picture)
.
Pin 8, PWR_SW_N, Power switch low referenence pull down to ground
.
Pin 9, Reserved

 

I am not crazy about yanking wires while the system is running or even just plugged in. When you say it would restart after a minute or so, do you mean it would restart by itself? If it does, then I would suspect a stuck switch.

Sadly, the ATX Form Factor Standard does not specify a standard labeling convention for ATX motherboards or cases so makers just use their own and leave it to users to sort it out.

I can help with that.

P = positive, +
N = negative, -
Slp = sleep
High = positive, +
Low = negative, -

I have never seen (or maybe just not noticed) "pull high" and "pull low" used in this way but in this context, it means positive or negative respectively. In digital electronics, a "high" represents a data value of 1 and a "low" a 0. There may not be any negative voltages. A high might be +5V while a low might be 0V. Or even a +10V for a high and +5V for a low.

I have two concerns with your problem, (1) heat and (2) standoffs. (1) Did you properly apply a fresh "new" layer of thermal interface material? See my canned text on TIM here. (2) Note that cases are designed to support 1000s of motherboards so there are almost always more mounting holes in the case than there are in the motherboard. Also note the ATX Form Factor does not dictate that motherboards have mounting holes, only that if a hole is present, it must be in a specific spot. This means and often results, if the assembler is not careful, extra standoffs under the motherboard which can short critical circuits. It is quite possible your old motherboard had a mounting hole where your new board does not. And if you left it there, it may be shorting out the board. You must be 200% sure the only standoffs in the case under the board match with a corresponding mounting hole on the board.

 

Thank you Digerati for your comprehensive reply, I shall read carefully and inwardly digest, If I can sort the problem, I'll let you know.

 

And for the record, concerning your identical post at WindowsBBS, I did not search the forums for identical posts. I subscribe to both forums so I get email notifications of new posts and that's how I found both.

 

I seem to have progressed a bit as instead of a totally dead PC, I now have all fans running, HDDs seem to be running (difficult as they were always very quiet).. After putting everything back in the case and booting up, I get the following symptoms:- 1) the MSI opening splash screen appears and just hangs.
2) the keyboard appears to be dead, no lights etc but, strangely, if I press and hold "TAB", I get the ami bios screen which says "Checking NVRAM" and hangs there.
Any further suggestions appreciated.
This enquiry is not posted anywhere else

 

Many times a change in mother boards requires a reinstall of the system, it is wise to always replace with the same make and model the slightest variation in hte MBR can make the difference. What you can try that may work is to repair rather than reinstall, it may rewrite the MBR and get you through.

Phil