PC Boot Issues


I hope someone may be able to give me a few pointers on how to procede with my issues. I will avoid to write a novel like I usually do ;)

My problem is that every so often my PC basically refuses to boot. It will start spinning the fans, the HDs and DVD will light up for about 2 seconds, I hear the HD spin and then it simply does nothing anymore. The HD stops spinning, the HD light goes off, and the screen stays black.

This happens about once every 2 weeks. And it can last from one hour to one or two days. After that the PC suddenly boots again and it pretends nothing has happened. It's like your car that won't start for some reason every once in a while :)

This is what I've tried so far:
- rebooting / resetting
- CMOS reset
- removing everything but power supply, videocard, motherboard, CPU and RAM
- switching RAM modules
- buying a UPS (which seemed to work for the first two months and I was very happy, until the PC decided that wasn't it and refused to boot again)

When it is working it sometimes freezes as well, either in a game or just when idle. It doesn't overheat. The CPU and GPU are at normal operating temperatures.

I can definitely say it's not a software problem since this occurs before any OS is loaded. And it can't be anything else than the aforementioned components that I didn't remove. However, I currently don't have any replacement hardware so I cannot start testing.

The PC will suddenly work again without any changes made, so it's difficult to test. Once, after a 3-day 'refusal to go to work' I decided to simply bring it my PC shop as I had enough, but right putting it in my car I did a last test and... it worked again.

So now, after refusing to boot for two days, I thought I'd get some help on the forums :)

I have an Asus P5B motherboard, with an Intel Core2Duo E6600, 2x1GB Corsair DDR2, an ATI Radeon HD 4850 and a 600W OCZ power supply. This is my third videocard on this system as my GeForce 7900GT and GeForce 8800GTS both died (they gave artifacts) and my second power supply as the previous one exploded right in front of me.

I moved now, but I think I had some serious power issues in my previous appartment which may have caused damage. Hence the UPS :)

Any idea what it might be? Perhaps the CPU and motherboard sustained damage from bad current and therefore sometimes refuse to work? How can I test the components without having hardware replacements?

Hopefully someone can help me a bit. I only use my PC to play an occasional game and to do Windows programming. So I don't feel like buying an entire new motherboard/CPU/memory configuration while this system will do. For the rest I use my Mac, which luckily (still) works fine at the moment :).

I hardly ever have software problems, but I seem to attract hardware problems a lot instead. The number of motherboard, videocard and CPU failures I've encountered on my PCs were numerous :).

Thanks a lot if someone can give me some pointers or info on how to know which part is failing. I usually work by elimination, but at the moment I'm stuck eliminating any further.

Best regards,
8 answers Last reply
More about boot issues
  1. In my experience, problems like this are most often caused by RAM problems. What are the exact specs of your RAM? Did you manually set the RAM speed/timings/voltage to the manufacturer's recommended specs in the BIOS? Have you run Memtest86+ overnight to test for RAM errors? This checklist has additional troubleshooting ideas:

  2. Hi,

    Thanks for your reply.

    I have 2 modules of Corsair Dual Channel TWINX 1024MB PC6400 DDR2 800MHz. I manually put the speed and timings. Can't remember about the voltage anymore but I presume I put them correctly (IIRC it is 2.1 volt which is set by default on the motherboard).

    Once my PC boots again I will let Memtest run. When it won't boot I never get to any BIOS or video output, so I will have to wait until it 'magically' works again :)

    I've done pretty much everything in the checklist you mentioned. I don't have a speaker however, so I can't check for beeps.

    Now that I think of it, I do get the occasional blue screen when Windows crashes. When it happens the system just freezes, but sometimes when shutting down the blue screen appears with often a different error. It varies between the USB, some network.sys file... which led me to believe it was a motherboard issue. But it would actually be great if it were the RAM, as it's the cheapest thing to replace :D

    Thanks for the suggestion, I'll get back to you once I've done the memtest. Let's hope my PC will boot again this evening :)
  3. Might also be a grounding issue, I have one with my system that does the same thing. It works just fine when I hook it up to a 220 to 110 convertor tho. I blew through 3 PSU's thanks to faulty German power. What case do you have? I had no issues till I started using a case with a bottom mounted PSU. (Antec 900, then a 1200)
  4. I first had a Chieftec case with a Thermaltake Butterfly 480W PSU. I replaced the PSU with an OCZ GameXStream 600W and later I bought a new case: an Antec P182. It does have a bottom mounted PSU, but I doubt it matters whether it's in the bottom or top of the case?

    I currently live in France where they use 230 Volts like in Belgium and the Netherlands where I lived before. I don't really know a lot about electricity, but they all have a grounded plug: http://users.telenet.be/worldstandards/electricity.htm#plugs_e

    'Funny' anecdote about how the first PSU died. When coming home from holidays I plugged in my PC and clicked the PSU button. I didn't even turn on the PC, just switched the PSU to the on (I) sign. Suddenly huge sparks and flashes were coming out of it! I was on my knees under my desk to plug it in, so it happened about 30cms from my head. I didn't dare to click the button again out of fear of electrocuting myself, so I pulled the plug from the PSU. After that all the lights were out in my appartment and I had to go to the basement to reset the electric switches. So I was pretty scared this would have damaged the entire PC or blown up the HDs, but everything still worked.

    I think I can relate most of my past hardware issues to faulty current in my previous appartment. Before I moved there I never had a single hardware issue, and suddenly things started. At least the following died on me: 2 GPUs, 1 CPU, 1 motherboard, 1 PSU. Sometimes the lights slightly dimmed for a fraction of a second. Just enough that you notice it. And sometimes when plugging something in the wall socket I could see electric sparks. That's why I bought a UPS to make sure the current stays stable and to prevent electric shocks.

    Weird enough is that I had the exact same problem with my previous system a few years ago (AMD 2400+) that it often wouldn't turn on / boot, until it finally never turned on anymore and I bought my current system. In that case it was the CPU that died.

    Thanks for the reply.

    **edit** Just noticed your avatar. PlaneScape Torment, fantastic game ;)
  5. I wonder if the PCI slot your gfx cards are going into is bad or has an intermittent short? Considering all your other hardware failures, I strongly suspect you have a bad motherboard. That seems to be the one consistency in all the iterations of your system. In which case, a new motherboard would probably solve your issues, and would be $60 or whatever well spent
  6. Alrighty, a small update. I had a bit of time to mess around with my PC yesterday.

    After 3 days of not turning on again, I started unplugging the components again to see if I could resuscitate it back to life :)

    - Removing all HDs and the DVD did nothing.
    - Removing one of the 2 RAM bars did something: the screen gave signs of life as I saw a bit of BIOS/commandline output. It didn't do a lot more though as it was stuck at the USB port checking (or something similar). Rebooting didn't do anything anymore as the screen didn't go on.
    - Removing the first RAM bar and replacing it by the second brought the PC back to life and I managed to get into BIOS. Then I looked up the correct voltage settings, but in the meantime BIOS was stuck again.
    - Rebooting worked, and I put the correct settings. I wasn't totally sure about the voltage of the CPU anymore, but after some searching online (and reading all kinds of different answers in forum posts :p) I put the e6600 to 1.3V and the RAM to 1.8V.

    The entire evening my PC continued to work! So basically the only difference is that I switched the RAM modules and put the CPU and RAM voltage manually (I think it always was on Auto before as I don't quite remember ever setting the voltage, just the speed). This evening I will burn a memtest CD and let it run. Curious to see the results.

    If the RAM shows no errors I can probably relate it to the motherboard. Maybe it doesn't always power correctly, or setting the voltage to Auto may have caused too much or not enough voltage to run through the components, causing the crashes and issues with booting. Just some of my assumptions ;)

    I'll keep you posted on the progress. Already thanks for all the replies. I don't spend a lot of time on hardware forums anymore as I don't have the time (or perhaps the interest) to keep up to date on everything like I used to, but it's great to see the interest here and to get replies so quickly all the time :)
  7. After more than 40 years in the military electronics business, I can say that intermittent problems are about the hardest problems to troubleshoot. My only advice is to keep trying and start keeping detailed notes of what seems to work and what doesn't.
  8. Somehow that doesn't make me feel any better jsc :D

    I let memtest run through the night. This morning it had run for 10 hours and did 18 tests, all of which it had passed. So I guess we can pretty much eliminate RAM issues?

    Which leaves the motherboard, CPU, PSU and videocard. I doubt it's the latter as (if I recall correctly) the issues also appeared when I had my previous videocards. The PSU is unlikely I guess, since I simply changed the RAM bars around and (for) now the PC works again. If it were the PSU I doubt it would suddenly turn on again after swapping the RAM.

    This leaves the CPU and the motherboard. I have had these issues before where it turned out to be the CPU (then I had a replacement CPU to test), but not sure whether that would be the case again. The RAM switching really made me think it was the motherboard, as already suggested by some. This might also explain the different blue screen errors that appeared.

    So perhaps I should simply replace the motherboard before it does any more damage? For sure I will wait until the non-boot issue happens again, to be sure it's not simply solved by setting different voltages :). But if it does happen again I just need to be convinced enough that this is the issue. If it turns out to be the CPU I'll be replacing both the motherboard and CPU, while instead I could have simply bought newer versions (Core i5 or something) for a reasonable price :)

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