What could cause intermittant failure to POST?

[ShallowHal]

I've gone through numerous troubleshooting but still can't figure out why my PC will fail to get through POST periodically. Any ideas?

 

[Olias]

Since my crystal ball is in the shop, some details about your system would help. :disgust:

 

[Olias]

PS: nice sig, I'll have to change mine now. :|

 

[ShallowHal]

Thanks for the response. I gave up hope yesterday. Hopefully you see this. I'll try to give you a little background.
The Rig:
XP1700 w/included heatsink (not overclocked)
Shuttle AK31 rev 3.1
256mb Crucial PC2100
40gb Maxtor Diamond Plus HD
Visiontek 64mb Geforce2 DDR vid card
Windows 2k
PCI modem
PCI sound card

I put everything together myself (not my first time)
and it all booted up perfectly the first time.
Loaded some software (Office 2k, Visio)


All was still fine.

Next day I powered on the PC and it stalled before it
made it through post. No video but all the fans were still humming away.
Tried it a few more times and nothing. Came back later (about an hour) tried it again and it booted up perfectly. About a week of this same behavior went by. I tried removing various cards, tried a different vid card, still the same intermittent failure. So I RMA the mobo, got the new one back, installed it, (this time I used Arctic Silver II after removing the little pink patch on the heatsink and thoroghly cleaning the cpu) but I still got the same problem. Replaced the 300 watt Codegen P/S with an Enermax 350 watt p/s (as recommended by AMD) same problem. I'm out of ideas.


One more piece of info, It never fails POST when I restart. Only from a cold boot. Even if I get it to boot up, then shut it completely down, and try to boot up again, it sometimes fails. ANYONE

 

[Olias]

Sorry man, I can see you've gone though all the obvious culprits. Maybe try the mobo out of the case and only hook-up the power switch (no reset, spkr or LED's)

 

[CdnMade]

Tis is my first post in this part of the furum but here goes.

as sill as it may seem it could very well be your IDE cable. in the last few months i have seen at work 3 systems that acted closely to the way yours is. I would also bet that the ide cables are the same for both times you rebuilt the system. I came to this conclusion after spending alot of hours trying to figure why the hell a customers system would fail to post somtimes ant other times work great.

For you its a long shot but hey what do you have to lose

 

[TRCDROM]

As an A Plus instructor and without seeing your machine I can offer you the following advice.

When you say it does not post do you mean when you turn on the machine nothing happens or you dont see the post processess happening or is it something else.

If it is that the machine "wont start" There are three culprits I would look at first:

1) Make sure the RAM and the Processor are in the sockets tight - (apparently you did becuase you changed everything) If they are loose it may work intermittenly (sp?) - One of the things POST does even before displaying anything on your dsiaply is to check to see if the processor is there and if it is getting the correct power - WHICH BRINGS ME TO ISSUE 2

2) Verify the power supply in the case(again you did - you stated that you replaced it) Use a multimeter to check it?

3) Again with the processor. I have seen this many times. Check the fan on the processor. Do this first especially if when you boot the machine and it works correctly it and then all of a sudden acts strange and/or shuts down. Sometimes the fan on the processor either dies, becomes disconnected from the power or starts to work on and off. What will happen is that when the processor cools down it will allow you to boot the machine correctly and POST will happen. After the machine shuts down, (through user shutdown or because of the overheat) You will not be able to boot the machine until the processor cools again. Sometimes this can take under a 30 seconds and sometimes it takes a little longer to cool down
Once it cools down you will be able to use it again until it shuts down.

AGAIN - These are things I would look at first. Remember that I do not know what you mean when you state that it will not pass POST and also without seeing your machine to determine what else could be happening - These are just educated guesses

 

[ShallowHal]

Thanks for the replies. To CDNMADE thanks for the tip. I used a different IDE cable when I swapped the motherboard.
To TRCDROM, I'm probably not using the term POST correctly so I'll describe in detail. At any given time, cold boot or immediate shutdown, and then power up, the system will power up, fans blazing away, hard drive chattering, then it stalls. No video, no beeps, nothing. The fans are still humming away but the system refuses to go further. If the the system does come up, and I simply restart, it comes back every time. It only fails when I power up the system. Even then it's intermittent (thanks for the spelling). Two different power supplies and two motherboards have not changed the problem at all. What other information can I give out that will help solve this problem?

 

[ddeder]

I believe I am having the same darn problem with 2 newly built EPOX 8KHA+ machines. See my post here.

I have built quite a few new systems and have never had this problem before. These are the first two systems that I have built with the 8KHA+ and Athlon XP's though. Because I have tested everything else, I am going to flash the bios on the mobo (even though I currently have the most recent version) just to see if something in the ROM is corrupt. The EPOX website is down this weekend so I will have to wait until it comes back online.

By the way, once I am in Windows (XP Home Ed.), the computers both work fine.

I have also found that if I enter the bios and navigate around in the bios for more than say 30 seconds, the computer locks up right there in the bios every time.

One other thing, in the mobo manual it says that the 8KHA+ supports PC2100 modules with 2-2-2 timing. I bought my PC2100 DDR DRAM from Newegg but have no idea what the timing is (I don't recall this being covered by A+ either). Can someone explain to me what this timing is and then take a look at the 256MB Kingston DDR at Newegg and tell me if it is 2-2-2?

 

[Smurfwow]

I am having that problem aswell :/

Every now and then, my monitor will say "Signal missing" after i power up.

The fans are spinning, and i can hear the hdd spin up, but then it just freezes (windows doesn't start loading).


I get this more often after reboots that cold power ups.

my pc is:
tbird 1.33
soltek 75DRV (via based i think)
512 (2*256) nanya pc2400 ram
300W generic p/s
no sound card... i use the on board.
asus v8200 geforce3
realtek nic
ibm 75gxp 60gb.

 

[ddeder]

I have had a little breakthrough with my problem which sounds similar to yours. Don't know if it applies though as I am using a different mobo. I have posted what I have found here as I would like to get responses from other anandtechers that have my mobo.

 

[canadianpsycho]

Probably unrelated, but my XP CPU didn't fit as well into the socket. Had to ditch my swiftech HS+F, and I put a fair amount of pressure on the cpu when I closed the lever on the socket. Apparently the XPs are a bit thinner and some don't fit in the socket as well as T-birds (Had my problem on an 8K7A+)