Need assistance from expert: random crashes

I am using:

MB: ASRock 939NF4G-SATA2
CPU: Dual Core Athlon X2 3800+
PSU: enermax 350w

I am getting severe random crashes in my 4 years old rig. Sometimes, BIOS doesn't post. Sometimes, it freezes in the GRUB loader. Once, it even crashes during Ubuntu startup. I see some text indicating error from Ubuntu, but it blinks so bad that I couldn't make the sense out of it. Then, the whole screen becomes graphical mess. I don't see any Linux screen of death. On Windows, sometimes it crashes right durig the startup as well.

The computer can freeze anywhere, I can say. When it freezes, (if it survives to the OS) the mouse on the screen stops moving, and a few seconds later, keyboard stops responding. (pressing num lock = no change in num lock light)

I am thinking of 2 possibilities: aging power supply or malfunctioning motherboard.

Right now, I do not know how to test to indicate the problem exactly. I need your advice. Please teach me if you know something I don't in this case. What should I do?
27 answers Last reply Best Answer
More about need assistance expert random crashes
  1. Hi.

    Download and use memtes86+ for test ur RAM.
  2. Here's a question, I see you have a GT240, how long have you had that? Did you have it for a while before the problems? Were you seeing the problems without the GT240? The reason I ask is that the GT240 should be used on a PSU with a 12V rail capable of supplying at least 18A. Depending on how old your PSU is, it might not have the necessary 12V capabilities (my 430W only has a 18A 12V rail). Older PSUs tended to have more power on the 5V and 3.3V rails, because back then CPUs didn't always use the 12V rail. In otherwords, your GPU might be overtaxing your PSU, the PSU might not necessarily be bad. Just a theory.

    Otherwise, how well are your CPU and GPU fans running? Is there a fan on the motherboard chipset, and is that still running? Is anything excessively hot to the touch?

    You can try memtest86+ like saint19 mentioned. If you can run it for a couple hours without any errors, you'll at least know the memory is good. If it crashes, well, I guess that wouldn't tell you much (except that its not your HDDs).

    If your PSU is working and has enough power for your GT240, I would guess its the motherboard. At that point, is it worth looking for replacement parts (good luck with 939) when a newer AM2/DDR2 mobo, cpu, and memory could be had for maybe $200, and that would outperform your current system?
  3. I suppose I should give you the test steps I would take:

    First, I would check to see if all my component fans are running (CPU, GPU, motherboard, PSU). I would touch the heatsinks on my CPU, motherboard, and GPU to see if they are hot. If its hot to the touch (warm is fine, hot is bad), you might have an overheating problem. You can use Windows software utilities to monitor the temp while the computer is running, but if it crashes, those don't really do any good.

    If the temps look/feel fine, check out your PSU to determine your 12V rail amperage (should be on a sticker on the side). If the amps are too low (like <15A), you might need a more powerful PSU (you could find a 400W that has more 12V amps, we aren't talking a 1000W or anything). If you have onboard graphics (or an older, less powerful GPU card), try pulling out the GT240 and see if the problems persist. If you don't have any problems with the GT240 removed, you probably need the more powerful PSU (assuming the GT240 isn't overheating, hopefully you already checked that).

    If the GPU isn't the problem right away, unplug everything else you don't need (expansion cards, USB peripherals). You can use a memtest86+ CD (or the Ubuntu Live CD) to boot from, so you don't need any HDDs either. If your computer crashes without any peripherals installed, you at least know its not your HDD or sound card or something like that (my printer can actually prevent my computers from POSTing, I sent a mobo back to Gigabyte before I figured that one out, I keep the USB unplugged when not in use).

    If the peripherals aren't the problem and the GT240 isn't drawing too much power, check the PSU itself. IF you have an extra PSU somewhere (in another machine or in a closet or something), try swapping that out. See if the machine works with a different PSU.

    If you don't have access to another PSU, you can try testing the one you have first before buying another one. You can get a voltage tester at Best Buy or online for like $20 (but if a new PSU is $40 after rebate, maybe its not worth it, but if you have to replace the whole computer, why spend $40 on a PSU when you can get a whole refurb for like $300? decisions decisions). This will tell you if the voltages are the proper values. Be careful though, even if the tester says the voltages are OK, the PSU could still be bad because the tester doesn't draw power like your computer does. The tester only tells you if there is a problem, not that there isn't a problem (if that makes sense). You could also use a multimeter or voltmeter if you have one of those. You can look online to see how to turn-on the PSU without connecting it to your motherboard (you have to short two pins together), and which pins carry which voltages.

    Otherwise, I'd have to guess its the motherboard/CPU/memory. If you can unplug all HDDs, your GPU (if you have onboard graphics), PCI cards, USB devices, etc.. (save for 1 CD drive or bootable USB drive), and memtest86+ or the Ubuntu Live CD can crash your system, its gotta be one of those three. Depending on what components you have, swap out the memory (unless memtest ran without errors), CPU, and mobo. Unfortunately, though, with a 939 system, none of those components will be readily available. Unless you have other 939 parts, you might just have to replace all three components.
  4. I just got my hand on my desktop today, try turn it on and the result is, sometimes BIOS failed to post. If it posts, there are chances that it freezes at GRUB loader.

    I have the GT240 for a month now, and I've been playing games on ultra setting and the games never crash even once.

    Now, I cannot access my OS at all. It will crash at some points before OS can load.

    For programs like memtest, I couldn't get it running right now because sometimes BIOS does not post. I will try my luck some other time.
  5. For the temp, everything is running cool. All components are 35-45 c only.
  6. If you have some spare component try switching them out I would test the hard drive too.
  7. Ok, I got the memtest running after several resets. During the test, it doesn't freeze at all. 56 minutes passed and the program claimed that it passed the test. Ok, restarting...BIOS does not post again...all the initial text such as "press f2 to enter setup, etc" are displayed, but it just freezes there.

    It seems RAM isn't the problem here.
  8. You still haven't mentioned what your PSU is rated at, and then based on that answer whether or not you've tried another lower power card/onboard gfx to see if it's more stable

    I wouldn't be surprised if you can't get into your OS now at all, it's not going to like continually crashing and that will eventually mess up some system files eventually.

    Also, just because it ran for a month doesn't mean it was neccesarily right to begin with. I had a friend who decided to use 1 5V rail with about 3 molex adapters to power a gtx 260, his arguement was that it couldn't be his fault or the psu's because it'd been working for awhile beforehand. This was before I took it apart (and i mean properly checked over the wiring in the 5v rails) and found he'd basically toasted the copper, lost a wire or two (almost unnoticeable) and as soon as it was under any kind of load his pc would crash.

    However the lack of POST is a little worrying. You really need to see if you could post with another gfx card. You basically need to get a friend and start swapping parts until you find it comes back to life. Only until you've switched the gfx and/or psu will you really start being able to nail it down to the motherboard. If crashes are truely random it always makes me suspect the PSU to be honest.

    What I also think you need to do is next time your board is not posting, pull out all the RAM and try to boot - you should hear bios beeps, if not, i'd say your mobo ain't fairing too well

    all this stuff is assuming you are trying a minimal boot as well btw.
  9. I need to ask a stupid question: I've bought my enermax for 4 years now and I only recall that it's 350w. How can we find other statistics? The product box and receipt are lost in, yeah, I don't know what my PSU is rated at.

    For the gfx, I will try the old x1600 tomorrow.
  10. As hellwig said
    "check out your PSU to determine your 12V rail amperage (should be on a sticker on the side).".

    Open up your case, there will be a sticker on the side of your psu with all the details on it
  11. About PSU: Just got myself the screw drivers kit, opening up the case, and it seems that I got this PSU:

    It seems my memory was wrong that I got 350w. It writes 460w... And I see that in the spec written at neweggs, 12v rail single is written. Is this what you are looking for?
  12. I also see that +12v got 35A in the DC input on the sticker. Is that enough for the GT240?
  13. 35A is more than enough to power the GPU.

    Try blacksheep's suggestions (pull out the memory). If it beeps multiple times without memory, then its at least trying to power-up.

    Still, the only way to know what is going on is to pull out the unnecessary parts, then start swapping the necessary ones (power supply, memory, CPU, etc..).
  14. Try removing the RAMs, the BIOS beep 3 times in a row, pause, and repeat the beep. After 3-4 repetitions, I shut it down and reinsert the RAMs.

    I cleaned the RAMs with eraser before putting them back in. Boot...1st detects my SATA and all those initial hardware, but it freezes there. Of course, BIOS does not POST.

    Try reset again...success...BIOS did post, but since my harddisks run in RAID 0 mode, I will need to set in the BIOS first.

    Try reset again, this time, I can enter my BIOS to set some values. (such as RAID and Legacy USB Support).

    Now, Ubuntu boots up, enter username, everything is running fine.

    Try Windows, it is also running ok for now... I will investigate further and see if it freezes again.

    For swapping graphics card, I haven't try that yet.
  15. Try restarting my machine and...somehow it failed to reboot. The computer shut down successfully but when it tried to boot again from the reboot, nothing comes up. The fans are still running, and my screen indicates no video signal is transferred at all.

    Once again, I hit reset button, this time, BIOS did post and I can get into Ubuntu. Browsing the web right now, I will see if I am getting more freeze...
  16. Ok, cleaning the RAMs does not help. Random freezes still persist. I will try do other things.
  17. Random freezes means CPU clock problem not RAM.
  18. ...changing my GFX card back to X1600. Well, I don't have any sort of crashes right now. I can boot into both OS pretty fine right now.

    Can a GT240 or any graphics card really make it so bad that the BIOS does not post ocasionally? I mean I got 35A and enough watts to feed it.
  19. The problem could be a driver problem from ATI to nVidia.
  20. I doubt drivers are causing problems in both Windows and Ubuntu and preventing the computer from posting. I'm going to have to say that either the graphics card is bad, and affecting your motherboard (since it POSTs fine with the x1600 but not the GT240) or the motherboard itself is bad.

    Could your GT240 be causing the problems? Yes. The card could be bad and causing power problems on the board OR not properly acting as a video-card. It could also be the motherboard itself, maybe the GT240 is too powerful for the board (motherboards are supposed to be capable of supplying like 75W of power to the PCIe x16 slot). Therefore, the x1600 might be working just because it has less overall power demand and the motherboard can handle it.

    This is all just speculation, I couldn't really tell you what is ultimately causing the problem. If you have another motherboard or computer with PCIe, you can see if the GT240 works in that machine (any friends willing to let you try it out on their computers?). Could you get ahold of another GT240 or similarly powerful GPU (8800/9800GTX, Radeon 3800 or 4800 series)? You could see if your motherboard can handle these. Otherwise, you might be stuck with the x1600. I wouldn't buy another graphics card just to find out it was really your motherboard all along.
  21. What a strange story... I put GT240 back in, try booting it up, and somehow it works. I don't get random crashes now. This is the 2nd day and still no freezing at all. I can browse webs, play games, etc. just fine in both OS.

    However, I noticed one strange thing: when using GT240, the fans of the case seem to have an uncommon sound. Normally, when we boot a computer up, the fan should have a sound of y = x before becoming constant. However, in this case, I got a sound of y = sin(x) for 3/8 interval before becoming y = x from that point; and eventually constant. I am sorry that my explanation is hard to interpret, but do you understand?

    When using x1600, the sound is normal during startup.
  22. I think I get what you're saying with the fans. Definately sounds like a power thing (not necessarily a problem). When booting up, there's a lot of peak-power usage as each component ramps up. Because the GT240 is a lot more powerful than the x1600, it might not leave a lot of power for the rest of the system, thus the fans are not running at full speed (speeding-up then slowing-down, back and forth).

    Don't be misled by a couple days of success. A week from now it might die all over again (I sent one computer back to the OEM about 5 times over the course of a year until they finally replaced the motherboard, these issues are not easy to solve). Solving your problem might just necessitate some component replacement (PSU and/or motherboard).
  23. Hellwig, you are right. This is the 3rd day of putting GT240 back in, and I just got the first random freeze in Ubuntu while using Firefox.

    strangely and historically, why does it choose to freeze more often during web browsing? *scratches head*

    Also, does this imply that graphics card with external power connector is more stable?
  24. ionosphere said:
    Also, does this imply that graphics card with external power connector is more stable?

    Not necessarily. Yes, the external connector can supply more power, but the cards are usually designed to draw the 75W from the board, in addition to more power from the connector.

    Besides, we don't know if the motherboard is the problem, or if the power supply is the problem. It looks like you're not getting enough 12V amps for your GPU, but I couldn't tell you the root cause of the problem.
  25. Strange...this is the 9th day. It doesn't crash at all...
  26. Best answer
    Yeah, don't really know what's going on. If you have problems in the future, I can really only recommend a PSU and/or motherboard replacement. Good luck.
  27. Best answer selected by ionosphere.
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