# Solved: System won't POST, no display, no beep codes



## coolman7 (Apr 29, 2005)

Hello all,

I built a computer for my mom 6 months ago, and now it won't POST or show display or any beep codes. The last thing it showed on the display was the info when it POST's and then went blank.

The mobo is a GIGABYTE GA-7VT600P-RZ Socket A (Socket 462) VIA KT600 ATX AMD with 1 gig processor, with corsair memory (512) value select pc3200.

The power supply came with the case and I don't know the brand off hand.

I have not looked at the system yet, but I will check memory, video card and cables to make sure they are secure and reseat, and check power supply voltages. I'm pretty sure the monitor is good.

If there are any other things I can check, any help would be much appreciated.


Thanks!!


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## loserOlimbs (Jun 19, 2004)

Sounds like you know where you are going with this, but if you hit any speed bumps you know where to come.


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## Skivvywaver (Mar 18, 2001)

Yeah, you have a good handle on it. I'd check the power supply first, it is the most likely culprit. After you reseat the video card and ram of course.


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## coolman7 (Apr 29, 2005)

I checked all the things I know to check for this system. I verified RAM, Vid card, Hard drive, DVD ROM, FLOPPY and PSU and all are good in another machine. I verified that the standoffs for the MOBO were OK and none were touching the MOBO. I checked the PSU with it plugged into the MOBO and get 12v, 5v. and 3 volts.
I Purchased a new MOBO(ABIT NF7-S2G nforce 2 ), put the old porcessor in and it fried the new MOBO. I did not realize this until I bought another processor ( sempron socket A 2500 ) and it did not work. I took both the new MOBO and proc back to store and they verified the MOBO was bad and would not POST, and verified the processor was OK.
I bought another MOBO (ABIT NF7-S2G nforce 2 ) same as the first new one, and installed the new proc ( sempron socket A 2500 ) that was verified good and the same thing happens!!
No POST!
I have checked the LED's and switches for the case and they are not touching to ground, nor are the case fans.
Could it be the PSU causing the MOBO to fry or PSU and case? How could I check? the PSU came with the case(ANTEC).
The PSU is an ANTEC 350 Watt model SL350 smart power.

This one is killing me!!  

Any and all help would be much appreciated!


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## pronute (Feb 13, 2003)

Try clearing CMOS, then after the computer boots up reset the time and date and the processor speed, plus anything else relevant to your system specs.


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## coolman7 (Apr 29, 2005)

I did try and clear the cmos. The jumper is in the 1,2 position now and I tired several times to clear and reset the cmos from 1,2 to 2,3 and back to 1,2.


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## pronute (Feb 13, 2003)

Did you unplug the power supply first? And on some motherboards you have to remove the battery and reset the jumper. When your done resetting, the jumper should be put back on pins 1,2.


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## coolman7 (Apr 29, 2005)

I did unplug the psu, but did not remove the battery. would it make a difference to remove the battery?


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## VaporTrace (Aug 1, 2004)

Have you tried out of the case? 

I've had standoffs that were so short that the wire pins on the back of the MB actually touched the back plate which is why some vendors put a sheet of acetate on the back of the MB.

To save time on trouble machines I've tested with the board on the table top (formica covered) without any problems. Just be careful not to jarr any cards loose while powered up.
And don't forget to get back to basics for init testing: pwr, video, ram, kbd. Then start adding untill the problem returns. Reset CMOS. I use an LED to quick test the CMOS batt.

Good Luck


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## coolman7 (Apr 29, 2005)

I did try it out of the case , only after I installed it in the case and it did not work. I tired only vid card, keyboard, , ram and original psu, still the same no POST.


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## pronute (Feb 13, 2003)

Yes removing the battery will reset CMOS and resetting CMOS is the first thing you need to do to troubleshoot this, the reason for this is that with a locked Processor such as an Athlon, or Duron any unclean voltage, ripple, surges, etc. can cause a protection shut down. You must clear CMOS so you can reset the processors frequency back to normal. If this doesnt do the trick, try swapping the PSU for a known good one, if it still doesnt work, start disconnecting the drives, starting with the hard drive you wont be able to load the OS but you may at least get to POST. If it does then the hard drive is bad, if not eliminate another drive.


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## coolman7 (Apr 29, 2005)

I did try another known good PSU, but still the same. I will try and reset the cmos with battery out. Do you think the store that tested the other mobo they said was bad could have been a cmos reset problem. I watched them and I know they did not reset the cmos when they checked it.
I know all the other hardware is good as I tested it in another system, not a socket A so I can't test the proc.


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## qldit (Mar 18, 2005)

G'day coolman7, gee you are having fun there, I would be inclined to keep it out of the case, set up as a minimal operation with no drives or leads whatsoever, no cards fitted, just using the ondoard video and ensure power connections are correct.
Does this card have the separate four pin P4 type as well as the twenty pin?
It may be pertinent to reset the CMOS, using exactly the manual procedure. 
Having done this power the thing up and observe for any video or monitor Led change.
The pinouts for powering the thing will indicate which pins need to be momentarily shorted using absolute care!
Processors usually don't die easily, but you certainly are getting ito an odd situation with it.
Under no circumstances plug any items without removing the power entirely..
You are sure your monitor is good?
If no joy in this situation the next step becomes expensive unless you can get someone to try their processor in your system or try your processor in theirs.
I loaned an Athlon 1900 to a chap recently with a similar problem and was handed back a processor that for some reason no longer works.
In some cases it may be best to bite the bullet and progress to another board and another processor together simultaneously and live in happiness rather than the possibility of a ladder of damaged parts. Of course this is dependent on your religion being correct!!
Cheers, qldit.


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## coolman7 (Apr 29, 2005)

i did try the cmos rest again to no avail and my monitor is good. Do you think it would be a good idea, since i know all the other hardware is good, to exchange the proc and mobo for new ones and pick up a new case/psu? could the psu be causing a problem with damaging the mobo?

thanks


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## qldit (Mar 18, 2005)

G'day coolman, when you reach this situation anything is possible, unless you have sufficient parts to interchange for evaluation to determine what is wrong, it is often better to place a blanket over the components that are not working and replace everything underneath. This is technically referred to as "blanket fixing" and is very often the best solution.
Use absolute care, do nothing with a powered system, even if it is not switched on. (this is the greatest computer killer!)
Remember to discharge yourself and if you can, wear an anti-static wrist-strap connected to the machine. 
When you are working with milions of supercritical semi-conductors one "whoops" can be too much. I suspect you may have experienced a little touch of the domino theory.
Power supplies operate in a high frequency kind of switching mode where minimal components are needed, the things work pretty well, but do often have a habit of catastrophic kinds of failures that may damage downstream components.
This kind of failure commonly occurs when the power supply fan dies or the power supply components get too hot, it is usually accompanied by a lovely smell. 
Commiserations, qldit.


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## coolman7 (Apr 29, 2005)

I hear ya! I am going to get a new mobo, proc, PSU and a new case and retry it from there. I will let you know how it turns out ( good I am suspecting ).

Thanks for all your time and input!!


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## VaporTrace (Aug 1, 2004)

coolman7 said:


> i did try the cmos rest again to no avail and my monitor is good. Do you think it would be a good idea, since i know all the other hardware is good, to exchange the proc and mobo for new ones and pick up a new case/psu? could the psu be causing a problem with damaging the mobo?
> 
> thanks


Some CMOS require a restart with CMOS RS jumpered, power off, remove the jumper and power on again. Most CMOS will reset if you completely drain the pwr (powering off the surge suppressor rather than pwr btn), remove the CMOS batt and then try it without the CMOS batt. Reguardless, I've not seen a system yet that will retain CMOS 48 hours unplugged with the batt removed. (Those can't find docs, can't find reset solder pad, so just leave it over the week end).


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## coolman7 (Apr 29, 2005)

Well, I have a working system now. I ended up going out and buying a new mobo, proc (amd 754), and a new raidmax case with 400 watt psu. Installed all the old hardware ( except psu, case & mobo of course  ) and it works like a charm.
The old case must have been shorting out the mobo, or else the psu was shorting it, but I am leaning towards the case.

The old case I suspect of shorting my mobo's is an ANTEC SLK1650B with 350 watt ANTEC PSU - stay away from this product!! My faith in ANTEC has been lost!!

Oh well, I thank all of you for your time and help!!  :up:


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## qldit (Mar 18, 2005)

G'day coolman7, I think you are a very wise individual, quite obvioisly you had some really od problem there which you no doubt will eventually unravel.
This has been an excellent learning experience for you, so although you may have spent a few shekels, you are definitely a winner, I would compliment your actions.
Well done, cheers, qldit.


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## coolman7 (Apr 29, 2005)

Thanks qldit!! Much appreciated. This has been a very good learning experience  !!  

Thanks again for your support. :up:


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