PC getting power, but Mobo won't POST

I've had a problem going on for a while, but now it's critical. For the last few months my PC would take a few, then later several tries to get it to post after shutting it down for the night. My solution for the last month as been to leave it running all the time. Well.... I went for a while this evening and my wife turned off the PC because she said it was too loud. Now the thing won't post no matter how many times I try. I've reset the RAM, cleared the CMOS, unplugged the reset switch, but to no avail. The CPU fan is spinning fine. The MOBO doesn't have speaker (and from what I can tell no place to plug one in) to get beeps. I'm at a loss here. Can somebody give me some help please?

My system is listed in my signature.

57 answers Last reply
More about power mobo post
  1. This could be a lot of 'bad' things, faulty -> CPU, MOBO, PSU, GPU, USB.

    So lets try to root them out, since this is an essentially 'dead' system; pull the MOBO out and place on cardboard outside of the case {breadboarding}. Connect only the bare essentials first {MOBO, CPU, PSU, & HDD} ; yeah no GPU no Keyboard/mouse. Test to {hear} if starts - you can connect the power switch or better short the PW+|PW-.

    If still nothing, then 'borrow' as PSU from another rig.

    Post back & Good Luck!
  2. As jaq said, could be lots of stuff, and statistically the usual suspect is the psu. If you can't appropriate one for the test and must buy one, this would be the choice at today's Newegg prices:


    It will run any desktop with a single video card, and a spare psu is almost a necessary debugging tool anyhow lol.
  3. Well, the weird thing is, after trying about 50 times the system did actually POST sometime about midnight. I wish I could say it was something I did, but it wasn't. Before I got your responses and after I tried everything I wanted to get involved with that late at night, I was reduced to just trying to turn it on every couple of minutes. One time it worked. I think my procedure that time was, unplug power cable, plug in power cable, turn on from front case switch, turn off from PSU switch, turn on PSU switch then hit front case switch. I won't turn it off again until I need to try something to fix it. Which needs to be done ASAP. I've put it off too long as it is.

    Now, my PSU question. Even when the system won't POST it appears to be getting power to various things that are attached to the motherboard. For example the CPU cooler fan comes on and the monitor doesn't give me the "no signal" message. Could a problem with the PSU allow these things to function, but interfere with the POST process?
  4. Have you tried breadboarding?
  5. Your OCZ 700W GameXStream PSU is not the 'best' choice - 4 rails & 'seems' to lack Japanese capacitors, but has Active PFC. My assumption is that your PSU is putting 'dirty power' to the MOBO/CPU/GPU.

    And, 'if it were me' I would strip it down as I mentioned above {breadboarding}; otherwise there are too many variables to contend with to figure out what going wrong and root cause. I've seen a bad USB mouse cause post failures or similar peripherals problems.
  6. Warpspasm said:
    Well, the weird thing is, after trying about 50 times the system did actually POST sometime about midnight. . . . Could a problem with the PSU allow these things to function, but interfere with the POST process?
    First, be clear on one thing - the stranger the issue, the more likely its the psu. However, as said way up front it could be lots of things. We recently had one post failure with a PC hooked DVI-Monitor that was resolved by using a DVI-VGA adapter to the VGA port on the same monitor.

    The likely suspects are in priority sequence: PSU, motherboard (including CMOS), intermittent "short" somewhere else, something else.
  7. Now that the system is actually running, I'm leery to breadboard it by taking the mobo out of the case completely. Can't I leave it in the case and take everything off of it? Don't I need also to keep at least one stick of RAM on there?

    Also, if I have to replace the PSU, can you suggest a good one? The one suggested by Twoboxer sounded great until I read a couple of reviews saying the cables were too short. My Cooler Master 830 EVO case is enormous, so it would probably be a problem.
  8. {breadboarding}. Connect only the bare essentials first {MOBO, CPU, PSU, & HDD & RAM - minimum} - RAM my over site; yes you need RAM to post.

    Yanking out the MOBO isn't that difficult; 15-20 minutes versus now 2+ days of posting.

    PSU replacements; I would go the TX650W I adjusted for both CPU & GPU OC {not extreme}. The Corsair has the ideal 1 Rail + Japanese capacitors and protection for PSU failure.
    Corsair 550VX - $80 - http://www.newegg.com/Product/Product.aspx?Item=N82E16817139004&Tpk=corsair%20550%20w
    Corsair TX650W - $90 - http://www.newegg.com/Product/Product.aspx?Item=N82E16817139005&Tpk=TX650W
    Corsair HX650W - $120 - http://www.newegg.com/Product/Product.aspx?Item=N82E16817139012&Tpk=HX650W
  9. So then, if I only use the MOBO, CPU, PSU, & HDD & RAM and it won't start the HD booting, then that means it's one of those components. I guess I have to then start trying alternates to each of them to figure it out, right? I guess I'd pick up the Corsair HX650W at that point. Hmmm... if it's the motherboard, I might build a new system, since mine is a little long in the tooth anyway.
  10. Unfortunately, the only way to know 100% is to 'borrow' components or 'swapping' components in a known good PC.

    Based upon the fact that you could boot "Now that the system is actually running, I'm leery" gives me a strong feeling of a bad PSU. {idea, if can buy the Corsair locally and it doesn't work return the PSU; Best Buy does carry the Corsair 650W}

    Good Luck! Let us know...
  11. I do have an older HP PC in the back room that used to belong to my son. It has a measly 250W PSU, but do you think that would be powerful enough just to use as a test for my system?
  12. Duh, it's right on the borderline; couldn't hurt to try. I know an non OC with 1 HDD and a simple GPU would work @ 300W. It is something that I would try to possibly rule-out a bad PSU. If it boots then don't leave it running too long, but if it does boot then you know to replace your PSU and rest easy.

    Good Luck!
  13. oh dear. 250w? That might be enough to power...well nothing actually. Your graphics card might just suck up all 250w and not even turn on :P
  14. When I ran the numbers it came out as a 450W+. Flip a coin if it'll boot.
  15. Booting into safe mode avoids the graphics drivers loading and should restrict the gpu's power draw to not much more than idle. It *should* boot.

    It should also boot directly into Windows, though there may be a brief power surge as Windows loads the drivers - I don't know. But in any case, it should be very brief.

    Since Safe mode would prove the point, there's no need to try anything else. Strap up the 250W and boot into Safe mode.
  16. I was going to use it in a basic breadboard fashion (except leaving the mobo in the case). Only powering up the HD, CPU and RAM. If the HD sounds like it's booting, won't that mean it's NOT the PSU? Will the 250W power those components?
  17. The guys who are trying to help have a lot of experience doing this remote diagnosis stuff. There's a really good reason for taking it out of the case - it eliminates build errors and case issues which could be the cause of your problem.

    Your mobo will post with an error you can hear only on your motherboard speaker if there's no graphics adapter available. The HD isn't going to make any noises other than power on.

    The 250W psu will power your system, assuming its a standard ATX psu. It may or may not be happy in 3d graphics mode, hence the recommendation to boot into Safe Mode. But as I sadi earlier, it should boot into Windows as well - just don't do any graphics. This is a test.
  18. I understand that. The reason I don't think this is a build issue involving the mobo placement in the case is, this system has been operational for about 3 or 4 years. The last couple of months it has gotten progressively flaky. It could be a case problem, but I think it would be easier to just strip everything out while it's in the case and see what happens first. Then, if it still won't post and boot, it might be time to suspect a case issue.

    This motherboard doesn't have a speaker unfortunately. Not sure what to do about that.

    If it were to boot into Windows, the HD does make sounds. You can hear it reading.
  19. You gave us info we did not have - the build is old. it's reasonable to leave it in the case, unless its taken a hit recently.

    Sometimes its helpful to hear what Post has to say when it doesn't boot . . . like when you have no graphics adapter.

    It won't boot to windows without a graphics adapter. So without a graphics adapter, the HD will not click-click, and you will learn nothing.
  20. Actually, in my first post I mentioned that this problem started months ago, but we've had so many replies since then, I can see why that information got forgotten. And I didn't say originally that the system ran fine for a long period of time. My mistake.

    I need to find a little case speaker to put on the motherboard. I never did like the fact that this one didn't come with one. I also may swing by Best Buy today to see if they have the Corsair PSU in stock. As somebody said, it would be a good idea to have one for trouble shooting anyway. I wonder if Best Buy sells case speakers. Maybe Radio Shack?
  21. Warpspasm said:
    I understand that. The reason I don't think this is a build issue involving the mobo placement in the case is, this system has been operational for about 3 or 4 years. The last couple of months it has gotten progressively flaky.

    The reason for breadboarding is shorts can be minimal in the case and progressively cause PSU failure and depending upon the severity cause sporadic and undetermined failure(s).

    Not all PSUs die instantly some can cause unexpected shutdowns, partial failures etc.

    The removal from the case is to eliminate shorts, groundings, etc from BOTH mounting points and I/O shields. Some cases use 'odd' pins and some are not even pins but instead 'stamped' metal protrusions which are too large and require insulation {e.g. plastic washers, etc}.

    More than likely, your PSU needs to be replaced.

    BTW - the examples are all based upon real posts; the 'stamped' was solved by my suggestion of strips of electrical tape {the OP was ready to dispose of an entire rig over 3 cents of insulating tape.
  22. I ordered the Corsair HX650 this afternoon. If it isn't a faulty power supply at least I'll have one to use for troubleshooting or for my next build. I'm actually surprised I haven't rebuilt this system yet. But, the older I get the harder I find it to justify replacing something that still meets my needs. I've gotten into a lot more photo editing, so a CPU upgrade may be in order though.
  23. Rigs are typically good for ~ 5 years, and yes I seen them last a lot longer. The cost of replacements are only justified by need and expectations.

    Also, the Corsair is a very good PSU and will outlive the next system and a half.

    Good Luck!
  24. @ jaquith - lol 5 years if the max for you.

    @ warp. nice choice, can't go wrong with corsair x)
  25. ^ As you we'll know, by now, I retire fully functioning rigs and I don't wait for them to fail. {Thankfully, I have some $ and that's what 'I' can do' for myself'} Older rigs - I get extremely worried about loosing or having my data corrupted. {Financials, Documents, Photos, Music, etc} BTW - they are ALL backed-up at least X1 per day and my 'work' {real-time backup} all including 'home' all run RAIDs/Home - home server back-up/Work - NAS + Data warehousing + off premises back-up via ~ NAS {The Planet}.

    If I had a fire or other catastrophic corruptions then I'd be out of business, and similarly I don't want to loose my daughter's baby pictures, etc.
  26. ^Wholy scat! wow - talk about hardcore backups. You sir are my idol! :lol: I'm actually gonna shell out a couple of hundred bucks to buy another hard drive or two. I'm just about to run out of space and need to make a full backup of everything. But it's nothing like what your doing lol xD. I backup everything once - but backup my important data three or more times.

    And that's something you cannot afford to lose! You should maybe put a few hard drives in a fire-proof case or something xD.
  27. If you lost the baby pictures - you'd sell your soul to get them back. Knock on wood never lost any data since the 90's and then I still had archived. We replace a drive every month or three in the office {part of a RAID}. If they fault there're yanked, if multiple fail the server gets yanked.
  28. Hey don't go all Dante up in here :lol: (Dante's Inferno? 'cept instead of going after a damsel in distress you're going after hard drives in boiling point temperatures =P)

    Do you do back-ups to a separate location or it's all just there on-site?
  29. ^ As I stated "off premises back-up via ~ NAS {The Planet}. "

    I'm just trying to put things in perspective of 'value' ; I have hard achieves via DVD-DL media and I'm looking into BR.
  30. Oh my bad. Seem to have skipped over that x).

    BR? They are like 25GB per side - i say it's a fairly good value. You could also back up the baby pictures there x)
  31. Well, it's not the power supply. I hooked up the Corsair and it's back to not posting again. I've tried running with all but one ram removed, no drives etc, but still no post.

    Here's something I've noticed, which may or may not be helpful. If I shut down my system and boot it again within a minute or so, it will start. But, if I let is sit for 10 minutes, the problem shows up. Could this be a clue?
  32. As I first stated "This could be a lot of 'bad' things, faulty -> CPU, MOBO, PSU, GPU, USB. "

    Are you certain this is NOT a thermal shutdown? Monitor the temps, if they quickly spike then replace the Thermal compound on the CPU.

    Also, have you EVER breadboarded - if NOT then NOW is a good time to start.
  33. I don't think it's a thermal shutdown, because it appears to fail starting when cold as opposed to hot. I guess it could be a reverse thermal start up. :) You're right about the breadboarding at this point. What do i have to lose? But, since the motherboard doesn't have any place for a speaker, and I have to take out the GPU, how will I know if it posts?

    Since there are so many things it could be, and this system is a bit old anyway, I might go for a new build. Here's a link to my thread I just started there if you'd like to help with that. I'd appreciate it.
  34. Quote:
    Now the thing won't post no matter how many times I try. I've reset the RAM, cleared the CMOS, unplugged the reset switch, but to no avail.

    Have you tried replacing the CMOS battery? It could be the CMOS battery is dead and when it boots, it's probably trying to reset to default settings.
  35. Hmmmm... good point. I haven't tried that.
  36. Nope. That wasn't it.
  37. Here's the latest. I took the system to a guy who has a Post board and it displayed the code C154. The trouble is, neither of us could find out what that code means. Also, I hooked up a case speaker and started the system. No beeps at all.
  38. Contact Gigabyte support with the post code, and post a message here:

  39. Hi warpspasm,

    My 10 month old Intel 860 system with an Asus Evo motherboard has 2 days ago started behaving exactly the same!
    Only on start up when cold.
    Have to unplug the PSU and press the reset button on the motherboard (sometimes several times!).
    Once up and running it is fine, but the thing I noticed is that when I first power on in the morning the Sapphire 5870's
    fan is often going at full speed and and not advancing beyond that point and perhaps that is maybe where the issue is occuring!
    I'll try another graphics card when I have the time.
    I didn't notice in your posts if you had the same graphics card fan issue or if have tried another card.

    Regards keith263
  40. Forgot to mention if left alone in this pre post state, it sometimes go into an OFF then ON cycle.

    Regards keith263
  41. Keith, I didn't notice the GPU fan because it's pointing towards the bottom of the case and I have so darn many other fans in the case I can't really hear it either. But, I did try a different GPU at one point and the problem is still there. Except now mine won't POST at all anymore.
  42. This could be a lot of 'bad' things, faulty -> CPU, MOBO, PSU, GPU, USB.

    Did you ever breadboard yet?

    {my wife had surgery a few days ago, so I'm not online much now...}
  43. ^ Tell your wife we all at THF said get well soon. ;)
  44. Shadow703793 said:
    ^ Tell your wife we all at THF said get well soon. ;)

    ^ x2 I'm with shadow mate! :) Hope she's doing well!
  45. :) Thanks - she's in pain and still nauseous, but she'll be fine in a couple of weeks! :)
  46. jaquith said:
    :) Thanks - she's in pain and still nauseous, but she'll be fine in a couple of weeks! :)

    That's good to hear! :D Great to know she's doing well x)
  47. jaquith said:
    This could be a lot of 'bad' things, faulty -> CPU, MOBO, PSU, GPU, USB.

    Did you ever breadboard yet?

    {my wife had surgery a few days ago, so I'm not online much now...}

    I think I just got it worked out! I resigned myself to the fact I was going to have to just rebuild the system and was doing some research on RAM. In one forum post a guy was talking about having "cold boot" problems as a result of some new RAM he bought. It was Crucial RAM, which is what I have. On a hunch, I started looking into this being a problem with Crucial RAM and sure enough it came up enough in forums and reviews that I was curious. I pulled both sticks or Crucial RAM out of my system and put in a stick of Kingston from my son's system. Turned it on, it posted normally and booted to Windows. What threw me off in the troubleshooting was, I was removing one stick of Crucial at a time, trying to isolate if one of the sticks was bad. I NEVER expected both of them to go hinky on me! I have a few more things to do before I'm positive this is the problem, but I'm pretty darn sure at this point. Weird one.
  48. Typically, not all at once unless the PSU failed/spiked and destroyed the RAM. I did not focus on the RAM because of the (one stick).

    Before concluding RAM, run Memtest one stick or you can try all sticks. Create a bootable CD/DVD {ISO/zip} - http://www.memtest.org/

    Is your MOBO GA-P35-DS3L? {listed as GA-P35-D3SL} Tested RAM - http://www.crucial.com/store/listparts.aspx?model=GA-P35-DS3L%20(rev.%201.0)
  49. Yep, right MOBO, but I'm (or WAS) using Crucial Ballistix RAM. I just tried taking out the Kingston stick and put back one of the Ballistix sticks and the system posted then froze trying to launch Windows. Put the Kingston stick back in and it booted right up.
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