Computer refuses to post

K

KillerPotato

Limp Gawd
Joined
May 14, 2005
Messages
167
I just got home today and as soon as i pressed the power button, I felt a little shock of static electricity. This has happened several times before, so I wasnt too worried. I left and came back expecting it to be booted up, but the monitor power light was blinking and wasnt getting a signal. I shut it down and restarted it, and the same thing happened. I tried with another monitor and still no signal. I'm afraid it might be the motherboard because normally when I power on, the CPU fan will go to maximum speed, and then almost stops itself because its the cpu's still cold according to its temp sensors. However, now when I start it up, the fan just keeps running at max speed. I'm not quite sure what the problem could be other than that though; I dont really have any spare parts to test anything other than possibly RAM (and it would be at different speeds),but I'll go poking around to see if I notice anything else that strikes me as peculiar.

My specs:
Chaintech VNF4 nForce 4 Ultra
PCI-E ATI X800XL 256 MB
1gb (2x512) PC3200 Corsair ValueSelect
AMD Athlon 64 3000+ socket 939
A couple HDD's
 
I would try to rule out RAM first since it is the easiest to test. Remove one stick and fire it up. If that doesn't work, try the other stick.

I once had a bad stick of RAM that was causing the same symptoms (not posting).

It may very well be something else that is wrong but it is a good place to start.
 
Thanks for the reply.

I just tried switching out the different RAM sticks and then tried a stick from an older computer, but to no avail. I might end up calling up a friend who also has a fairly recent computer and ask him to bring it over to switch up parts until I can get it working. Is there anything else that I should try first though to see if I can narrow down the problem without my friend's help? Thanks in advance!
 
I'm afraid so, but I still need to know what needs to get replaced. It would be sad if it was the motherboard, since this would be the second time it needs to be replaced; the first one was DOA, and I guess now its my fault this one's dead. Also sad since this would be the first time my random electric shocks did something :(
 
This is kinda O/T

Static from your body should not beable to pass to the mainboard.

Unless.

your PSU case is not grounded hence your system is not grounded and the only place for the static electricity to go is though your mainboard to earth.

if you want to test the grouding on your case just unplug your PSU press the power button a few time to discharge any residual charge the machine/PSU may have, then with a multimeter on circut test or resistance (If you want to be technical) put it on the ground pin of the PSU then anywhere metal on the case.

There should be either Very little resistance or none at all, the earth is there to be the quickest and easiest point to ground (Which electricity prefers)
 
ryan_975 said:
unless the static traveled through te power switch leads to the mainboard terminal.
Click to expand...

Then the mainboard terminal would have to have lower resistance to ground than the case.

and considering the mainboard has resistors and transistors capactors, it's internal resistance is going to be alot higher than a peice of metal.

However if your case was not grounded then this is entirely possilble .
 
the power switch wouldn't necessarily be grounded to the case. And electricity doesn't just travel the path of least resistance. Just look at voltage dividers. It travels all paths, but when a path is presented with no resistance all other paths have negligible current. But when talking about static charges of 5000-15000v neglible can be 40-50 volts. That can zap a system design to run on 3.3-12v. Maybe not at once, but he did say it's happened a few times before. So 40v here, and 40v there can wear a cicuit down. That last zap may have been just enough to kill something. And with a highly interconnected system like a motherboard, anything can be zapped.

Also it seems that he does a bit of work on his own system. If he's having problems with static than the power button wouldn't be the only thing affected.

Ryan
 
One more thing, Before you continue on I strongly recommend that you find out why you have such a problem with static and takes steps to remedy it. Otherwise you'll more than likely keep killing things.

Ryan
 
I'm gonna try to test the grounding right now if I can find my multimeter. Other than that though, is it a safe bet that the problem is the motherboard? Sadly, my warranty expired a week or two ago, so I will probably go ahead and buy a new one.
 
I tested the grounding and there is almost no resistance between the ground pin and the case. My front panel is completely plastic however, and I have a thermaltake 480W PSU if those are known to have problems with this sort of thing or something.

I think I'm gonna run down to Comp USA and see how much a board there is and maybe get one. The problem is, could the non-posting be related to the PSU or the processor? The last time I checked the Comp USA return policy sucked, so having to pay a large restocking fee wouldnt be ideal if the motherboard wasnt the problem.
 
No posting could be related to anything really, PSU, motherboard, RAM, video card, bad, etc The best way to find out which one iis the problem is to swap out part that you know are good. Start simple and work your way up. RAM first ,them the PSU, mext try the video card CPU, and motherboard.
 
KillerPotato said:
I tested the grounding and there is almost no resistance between the ground pin and the case. My front panel is completely plastic however, and I have a thermaltake 480W PSU if those are known to have problems with this sort of thing or something.

I think I'm gonna run down to Comp USA and see how much a board there is and maybe get one. The problem is, could the non-posting be related to the PSU or the processor? The last time I checked the Comp USA return policy sucked, so having to pay a large restocking fee wouldnt be ideal if the motherboard wasnt the problem.
Click to expand...

Chances are that your Power switch is/was not grouded and the charge only had one place to go.

As for the gradual 40V here and there Idea, I'm not too sure about that theory but it's entirly possible that the only place for the charge to go was though the main board seeing that your case is fronted with plastic and the charge could have caused a host of problems.

AS for future resolution of said problem you probably a bit like me prone to static buildup great fun a partys but a bugger for a sysadmin. however my solution was to buy a entirly aluminium case (Lain-li PC65B) and run seperate earth cables to the front panel and to the radiator HOUSE radiator which tend to be a great earth. and MY pc has not been zapped yet.
 
never mind

but i do have one idea....

what if cmos battery shorted? lost info for bios and as such your computer doesnt know its a computer, that might be fixed by simply replacing the battery. just a thought.
 
MrWizard6600 said:
never mind

but i do have one idea....

what if cmos battery shorted? lost info for bios and as such your computer doesnt know its a computer, that might be fixed by simply replacing the battery. just a thought.
Click to expand...

Actaully that would be a loss of the Basic Input Output System (BIOS) and the BIOS software or more correctly firmware is stored on a media called an EEPROM (Electrical Erasable Programmable Read Only Memory) this device is non volatile which means it does not lose information when power is lost, All the battery coveres is what settings to save. without the battery the machine with load fail-safe defaults and still continue to post and boot.

Personally I don't think it's going to be a problem with firmware I beleive it's probably an issue with hardware and it may be a combination of problems aswell I.E. CPU + MEM + Mainboard.
 
jnex26 said:
All the battery coveres is what settings to save. without the battery the machine with load fail-safe defaults and still continue to post and boot.
Click to expand...
Sorry don't mean to be rude, just a bit of clarification.

The battery just provides a backup power source to keep CMOS ram powered so that it doesn't lose its information. The battery doesn't have the settings on it itself.

I know that's what you said, but I just wanted to clear it up a bit for those who might not know.

Also I've run into a couple of computers that wouldn't POST without the battery in it. But they were older AT style motherboards.

Ryan
 
ryan_975 said:
Sorry don't mean to be rude, just a bit of clarification.

The battery just provides a backup power source to keep CMOS ram powered so that it doesn't lose its information. The battery doesn't have the settings on it itself.

I know that's what you said, but I just wanted to clear it up a bit for those who might not know.

Also I've run into a couple of computers that wouldn't POST without the battery in it. But they were older AT style motherboards.

Ryan
Click to expand...


Yes quite true I remember the days of the velcro backed battries that plugged onto the main board, however thoes were the days where setting the multiplyer was done with jumpers or dipswitches.
 
jnex26 said:
Yes quite true I remember the days of the velcro backed battries that plugged onto the main board, however thoes were the days where setting the multiplyer was done with jumpers or dipswitches.
Click to expand...
what's a multiplier? lol
 
ryan_975 said:
that wasn't a literal question. it was meant to illustrate how old of motherboards I was talking about.
Click to expand...

Todays mobos have multipliers too so you can see how I didn't catch your drift there.
 
Yeah, I figured that. I've worked on (and owned) some old 8088s through 486DX33s. They didn't have multipliers. The first x86 CPU that used a multiplier was either 50 or 66MHz 486DX/2-50. Even then the multiplier wasn't settable it was internaly done. But you could overclock them by raising the front side bus speed.
 
EDIT, Somehow this reply ended up triple posting. I don't know why, I only clicked submit once.
 
ryan_975 said:
Yeah, I figured that. I've worked on (and owned) some old 8088s through 486DX33s. They didn't have multipliers. The first x86 CPU that used a multiplier was either 50 or 66MHz 486DX/2-50. Even then the multiplier wasn't settable it was internaly done. But you could overclock them by raising the front side bus speed.
Click to expand...

Actaully, the 486DX-50 although when I got one it was the second fastest chip on the market, It's overclocking potential was rubbish as the FSB ran at 50Mhz and boy did I have all kinds of problems with PCI/ISA cards on that machine. However I do seem to remember messing with the multiplier on that machine. but alas it was 13 Years ago.

I eventually binned it for a Pentium-60 Greaaaaat move that was.....

But again Ryan and I have yet again De-railed This guys thread.

Have you any luck in gettiing your PC to POST
 
Thanks for all the input guys. I took the jump on buying a new motherboard (bought the ASUS nforce4 non-ultra board off of zipzoomfly since it had good reviews on newegg), and hope thats the problem since itll be fixed. I can still cancle the order if you guys can figure anything out of this: after it died, I wanted to get my medieval total war cd out of my dvd drive, but after powering the system on and having expected it not to post, the cd drive wouldnt respond to ejecting. Shouldnt the drive normally open even if the computer doesnt post as long as its plugged into the power supply? To get the cd back i plugged the dvd drive into an older computer using the same power supply I had used to power my newer but now fried computer, and the drive opened without complaint. I dont know if this provides any insight to what could be dead, but just in case, I thought it was a little strange.

If the motherboard turns out not to be the problem though, I'll just suck it up and pay the restocking fee since I dont have much of a way to test out all of the parts, and since my friends comp is an intel computer, all I would be able to test is the video card. Thanks again guys.
 
Well, I got the replacement motherboard this afternoon and set everything up and still no post. The thermalsensors for the cpu fan still never kick in, and now I've also noticed that the keyboard lights never flash on like they do immediately after I power on other computers. Also, I noticed that the light on the dvd drive when it was hooked up to the no-posting computer never turned green, and just wouldnt open, which I thought seemed strange. This leads me to think it's the power supply.

I was drawn away from blaming the power supply before because it would let my older socket A computer power on and post, but is it possible that it just cant power the somewhat newer parts in its possibly damaged condition? I've been running the thermaltake 480w for the past year without problems, although it is only a 20 pin psu running a 24 pin board, but is it possibly that some lines were zapped and now it just doesnt work with the load it's given?
 
I don't mean to sound too impatient, but if anyone has any input, please reply. I'm sort of worried that the problem could be the CPU, but with the symptoms described, I'm also leaning towards the powersupply. The problem is that I don't have any parts to swap out, and it's expensive to buy stuff and pay shipping to return it with a restocking fee. Does a dead CPU cause the same problems as I've described, or is it right now a safe bet to say its the power supply?

Another problem is that I'm leaving tomorrow for 11 days for a week of Habitat for Humanity and then for a school related national organization meeting thing, so I won't have much time before I have to return the motherboard or get stuck with it. I'm thinking I'll just send in the info to return the board, and then return it when I get back, and then wait on the PSU until afterwards. I'm still afraid of the problem being the CPU though, and I'm not sure if the PSU would even cause the problems described earlier, provided it still works on a somewhat older computer. Thanks in advance for any suggestions.
 
I just got back from a lengthy "vacation" (habitat for humanity and then a school competition in a nice hotel), and still no working computer. I ordered a power supply earlier today, but I also noticed that the dvd drive will now open on the new motherboard, but the only things the TT 480W PSU is driving are the motherboard, the dvd drive, and the 3 hard drives. This sort of worries me since this was one of the things pointing me towards the PSU as the problem. Does anyone have any sort of experience with this? Should I cancel my PSU order right now in favor of something that is more likely the problem? Any help is greatly appreciated,

Louis
 
Boy do I feel dumb.

It turns out it was the motherboard. It's just that when I got the new motherboard, I forgot to plug in the square 12v power connection on the motherboard after plugging in the main 24pin connection. Well, I'm not going to send back the powersupply since I probably need the upgrade from the thermaltake anyway (I got a nice Antect Truepower 550W, which should last me a while), and it was on sale so if I need to buy it in the future, it'd probably more than I paid now to begin with. You live and you learn I guess. Thanks for the help guys,

Louis
 
;) Hey these things happen.

I wont even get into some of things I have done. :rolleyes:

Glad you got it running.
 
You must log in or register to reply here.
Back
Top