POST problem with ECS Motherboard

[maltone]

I recently purchased an ECS K8M800-M2 MB and set it up on the bench with a Sempron 2800 processor and 512mb of suitable ram. All BIOS settings were default.

At first the MB did not POST - then I found the 12V aux PS plug was out 😳

After that all was well - POSTed, booted and ran my XP system fine.

When installed in the case - no POST although the fans were running and HD etc powered on. NO video on monitor etc. I used all the integrated peripherals.

Put MB on bench again out of case - still no POST.

Decided to try a CMOS clear, and then discovered that if the clear plug was pulled from pins 1 and 2, then simply reconnected to 1 and 2 while power on, - instant POST and all runs fine.

If a hard reset, or power off then on again, same problem - CMOS clear plug out and back in - away she goes.

Soft reset from windows OK.

What does the CMOS clr plug do when in pins 1&2? I tried doing a full cmos clear but did not solve problem. If the board is faulty, it is still under warranty, but I am intrigued. Battery? MB fault? Some strange bios setup?

Maltone

 

[Rogueone]

hmm. ok, very strange. have you tried with the cmos jumper removed. as far as I know, those pins are just holders. in the old days, there were only 2 pins, and the jumper just hung off one when not in use. sounds actually like some metal part got under the board when installed and caused some kind of short maybe. strange for sure.

 

[maltone]

Rogueone - thanks for the comment - yes it is strange. There is little info in the manual about CMOS reset - just short pins 2,3 with the power off - other notes I've read here suggest power plug out, leave overnight, remove lithium battery etc....... perhaps the pins 1,2 is actually supplying power to the cmos? Does the Power supply have a special cmos 'keep alive' supply even when the case is turned off? - if the cmos supply was 'weak', it may not work properly while powering up.

I may get out the multimeter and check some voltages.

Anyway, the store owner said he'd replace it. But I'd still like to find out what is happening.

Maltone

 

[Rogueone]

cmos should have a lithium battery, so about a 10 yr shelf life, powering it when there is no power from the PS.

 

[Oldguy]

A few months ago had similiar problems with ECS board and RMA'd. 2nd board operated for 3 days, then same issue. RMA'd that board, but needed a board "right now" so went to the local Fry's. They keep a LARGE supply of boards in stock but absolutely every single ECS board, no matter the model or socket was an "open box" return...I'm talkin over 35 boards here. Components Department manager claims the average ECS return rate is over 60% within 5 days of purchase. Their techs reseat and clear the cmos, pop them back in the box, cut the price 10% and back out on the floor WOW. ECS is supposed to be getting a lot better in the QC area, but they had a lot of room to work with. I would go RMA and hope for the best on the next one.