# Solved: Motherboard won't post



## BigDusty (Nov 30, 2010)

Hi all,

Would appreciate some help with this.

I have a Foxconn Motherboard N15235 and problems started with the computer freezing, it would freeze even when making adjustments in the BIOS, so I knew it was not a software problem regarding windows.

I disconnected everything that was attached, hard drives, optical drives, fans etc. Still froze.

I turned my attention to the Ram (4 X 1GB). Removed them all and put 1GB back in, ran a Mem test and all seemed fine. I put second back in, ran test and after half an hour it froze, so I thought Ram problem.

I put the ram into another machine and ran the same test and it was fine, passed the test and did not freeze.

OK, I next put different ram into the Foxconn Motherboard and ran the same test again, passed with no freezing. I started the computer up into windows 7 (fresh install btw) and tested the computer with a stress test, it worked fine for 3 hours with no probs.

I decided to put back in the old Ram and ran the same stress test and after half an hour the computer froze, this is weird!

After all this another problem arose, the motherboard will not post, all the fans come on but no beeps and the digital code reader built onto this MB comes up with --. If I leave the motherboard on for a while then turn it off and try again it will eventually post and boot up.

I have tested the power supply under stress and seems to be stable but could still be a suspect.

So, after all this (and thanks for reading and getting this far) I need a second opinion, new motherboard? Or is this there more I can do to be sure.

Thanks in advance for any help or advice.

Regards
BigD


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## etaf (Oct 2, 2003)

Have you checked the memory slots are clean and blow out (compressed air can) and make sure all clean 


> OK, I next put different ram into the Foxconn Motherboard and ran the same test again, passed with no freezing. I started the computer up into windows 7 (fresh install btw) and tested the computer with a stress test, it worked fine for 3 hours with no probs.


Have you put that "working" memory back into the mother board and run the tests again ?


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## crjdriver (Jan 2, 2001)

I would also give the board a VERY close inspection with a bright light. Look for any leaking/discolored/bulging capacitors. If you find any that look like the pics below, you have found your problem. In addition, have you swapped in a known good pw supply for testing?

FWIW foxconn quality runs the full gamut from very good high end boards to very low quality oem type boards [read junk]


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## BigDusty (Nov 30, 2010)

Hi,

Thanks for the replies and suggestions.

I have already checked the memory slots and have cleared all dirt and dust from them using compressed air.

I originally thought it may be a Ram problem but since fitting different Ram the computer no longer freezes which is very strange as the original Ram has been fine up till now and have not had a problem with it for three years.

It's as if I have cured the problem of freezing but have found another with the computer not posting only until after it has warmed up a bit then eventually will work.

In order to test the PSU using another, I have a spare PSU but only with a 4pin CPU connector as the motherboard and original PSU has an 8pin. 

I need to confirm before I test, will a 4pin CPU connector still work with an 8pin socket on the motherboard?

To get this computer to boot this is exactly what I have to do. Turn computer on, CPU fan spins and some led lights come on. Leave it running like this for a minute or two. Power down computer by pressing & holding the power switch. Switch on computer again and it will post and boot. Sometimes you may have to do this more than once for it to work. 

Regarding the capacitors, I took my time and they all seem ok, doesn't help the fact that there are so many of them.

Regards,

BigD


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## dustyjay (Jan 24, 2003)

Can you post the manufacturer and model number including wattage, and the Amperage on the +12Vdc rail(s)? I am going to go along with the part of crjdrivers thought about the power supply. A power supply problem can mimick many different problems.


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## BigDusty (Nov 30, 2010)

Hi dustyjay,
It's one of the first things that I look at is the Power supply but if this is at fault, it's a very subtle one.
This is the PSU installed; hope the info is all there
http://www.coolermaster.com/product.php?product_id=40
or if that link is a bit slow
http://www.xpcgear.com/rs500asaa.html
I am currently running the computer with a different PSU, but as mentioned before I only have a 4 pin CPU connector fitting into an 8pin socket.
The computer is running without any problems but I had to go through the usual palaver of warming it up first to get it to boot. 
FYI, I have tested the PSU whilst fitted with a multimeter and there is power and correct voltage going to all connectors. Have tested during and after fault and under stress.
Thanks,
BigD


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## crjdriver (Jan 2, 2001)

What you are describing [cold boot problem] is a classic pw supply issue. What happens is that when the psu is OFF, the caps inside slowly discharge. When you pw ON, the psu just does not have enough pw to boot the system. You then pw OFF or reboot and it works. The caps in the pw supply have a chance to build up a charge when it is on. This is why the second boot works.

As to whether or not it will work with a 4pin connector, most will however do check your mb manual.


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## BigDusty (Nov 30, 2010)

Hi all,

I'm with you all on this one, prime suspect is the power supply, common tell tale signs and power supplies can cause all manner of problems.

But what I still can't work out was the original problem with the original RAM (OCZ), it still does not like it and causes the computer to randomly freeze unless I swap them for similar but different make RAM (Corsair) then it behaves itself. I have the original OCZ RAM installed in another computer and that is running fine even under stress.

Anyway, I decided to bite the bullet and purchase a new Power supply (with an 8pin CPU connector)and to my surprise it does the same thing, won't post or boot unless left on to warm up first then retry to power up.

So, conclusion, it can't be the power supply, I've tried 3 different ones (including original) and I get the same faulty result.

FYI, I have even swapped and tested the CPU just in case and tried a different graphics card, it's not those.

I have tested everything (I think) and the only thing left is the good old Motherboard, Gulp!

Still open for ideas and options.

Thanks,

BigD


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## crjdriver (Jan 2, 2001)

I would then suspect your board is failing. As I posted foxconn makes a very wide range of boards from the very high end to very low quality boards.
From what I can find regarding specs on that board, it was originally an oem board from a PB system. If that is the case, I would NOT put any money into it since those are very low quality boards.


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## BigDusty (Nov 30, 2010)

Think I'll be throwing the towel in on this one, as you said the board is failing, slowly but surely and it can only get worse. 

Oh well, a chance for an upgrade, no point in replacing this board as now they are more expensive than a newer model and it will be nice to have Ram speeds of 1333MHz, that will be fast enough for me.

Many thanks to you all for your speedy responses and advice.

Cheers,

BigD

PS Should I put this post as solved?


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## crjdriver (Jan 2, 2001)

Sure you can mark it as solved. You can get some really great mb prices from newegg. I just bought a board for a htpc build and it was $69 plus $3 for shipping.


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## BigDusty (Nov 30, 2010)

Ok, I'll mark this Post as solved, due to faulty motherboard and replacement is my best option (upgrade actually) New Motherboard, 4GB Ram and CPU, the remainder of the computer will be suitable for now.

Not the end of the world for my old CPU & RAM, I'll find a new home for them.

I actually use Newegg allot for guidance and reviews, unfortunately I don't purchase from them as I live in the UK but it is a good site.

Looking at an Asus board SLI ready, AMD 3.2Ghz duel core and 4GB of 1333Mhz OCZ RAM £186.

That's not a bad price compared to what I was paying 3 - 4 years ago.

BigD


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