Advice needed: My computer won't start (black screen) totally randomly

bassport

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I know this sounds like a newbie problem (something wrong with RAM or video card etc), but the strange thing is that it's not really reproducable (so the solution can't be that obvious).

When I start my Comp (Quad Core 2.5 Q9300, MSI P7N Diamond (nVidia 780i, I think), 4 GB Mushkin RAM DDR2, FSB @ 1333, DRAM Freq @ 800) it works 1 out of about 3 tries. The other times it just does nothing (HD Led is steady on), I don't hear the HD's spinning up, but all the fans are running fine and the power is on.

IF the pc starts up everything seems to be fine. I get quite a good performance out of it and it doesn't crash often, so it can't be an overheating problem.

Could it have something to do with clock timings? I must admit that I pretty much have no idea how one does compute the FSB vs RAM timings (I didn't change anything though).

Any pointers what it might be are very appreciated!

Btw: I just bought a new video card (GTX-465) and the problem persists... can't be the card either.
 
It's probably your power supply test your current one in another computer or buy a PSU tester
 
I had the same intermittent symptoms myself with this current PC after I added a wireless LAN card with a 1x PCI-Express connector (the tiny slot usually in the vicinity of the more important Graphics cards slots). I never did get to the bottom of why this was happening exactly (perhaps a faulty card? faulty slot? power demand spikes in the card?) though I did find at least two other people reporting the exact same problem with the combination of the board type / card (this was rendered slightly less unlikely because the motherboard and card came from the same manufacturer. A- Bit I think).

The problem could well still exist in my system, because it was obviously a simple case of using another method for getting wireless (I went the USB route, PCI obviously still available. PCI-E was something I did mostly for novelty anyway). How does this map to your present situation? It's hard to say really. Try the long-winded process of running your PC without whatever expansion cards you have in there perhaps, because there could be a bad card in there somewhere causing you problems and as I've demonstrated, it doesn't need to be the most obvious, power hungry one (though if your PC is anything like mine, the GFX card is all you have anyway). Or because so far there's nothing to suggest a particular card is behind the trouble, see if you can run with a different Power Supply? At a stretch, it may be worth updating your BIOS.

It's probably notable that we have pretty similar systems (Quad Cores, 4GB RAM, though I have a AMD card rather than Nvidia), but I don't really have any conclusions to draw other than 'this shit happened to me too', because I sidestepped the problem as opposed to actually solving it.

As regards clock settings, you may want to take a look at what speed it's now saying, because IIRC, some of my repeated start-up problems resulted in the values being wiped from time to time (probably as a failsafe of some kind). Sorry I can't be of more help: because I purchased my PC overclocked, I made a point of writing down the settings shortly after booting it. I have no idea what they actually mean :p
 
I was going to suggest that you might simply have a bad power switch but then I noticed you said the fans all spin up.

Is your power supply adequate? BTW, what video card did you have previously? Because the one you have needs a really good PSU.

Could it have something to do with clock timings? I must admit that I pretty much have no idea how one does compute the FSB vs RAM timings (I didn't change anything though).
Pretty much. You need to set them correctly as a BIOS will usually get it wrong. So, look it up.
 
How many watts is your PSU? The GTX465 needs at least 550watts.
 
New video cards require a lot of amps. From my reseach a year ago, the amps on a PSU are more important than the wattage. That's why one 650w PSU might cost $50 and another will cost $125+.

I upgraded to a 650w PSU when I bought my Quad core and HD4850 - http://www.scan.co.uk/Product.aspx?WebProductID=684734&source=froogle

52A on a dedicated 12v rail (see Technical Specs).

Compared to this 650w - http://cgi.ebay.co.uk/650w-Quiet-Po...363677&cguid=2a82e0d712b0a47a2f733d63ffcbcebf

20A over two 12v rails.

If your hardware consumes more then it won't work, or won't work for long. And PSU's degrade over time.
 

I can't find the amperage in the spec list, which is kind of odd not to include.

Anyways, I would recommend giving this PSU a shot:

http://www.newegg.com/Product/Produ..._re=pc_power_&_cooling-_-17-703-027-_-Product

PC Power and Cooling (OCZ) is one of the premier PSU manufacturers. This one has 62.5A dedicated on the +12v rail. I have a similar PSU on my system with a GTX 470 overclocked, and it's 100% stable.
 
So you don't even get the bios to post? No beep codes or anything?
 
I can't find the amperage in the spec list, which is kind of odd not to include.
^Nice warranty on that.


54 amps * 12v = 648 watts (650 watts total)

x650.jpg



Look at the efficiency of this thing (which isn't its only strong point):

x650effeciencytest.jpg


They torture tested this PSU to 793.7w (to see if it burns or explodes - it didn't), and it still had 84% efficiency.

I would definitely recommend it if you can get it on sale. I got it for $119.99 with free shipping. If it wasn't on sale, I probably would have got something cheaper because: damn expensive.

It's good stuff, you should have no trouble finding reviews that say things like this:
Avert your eyes! The above shots are too awesome for human eyesight to tolerate!
In summary, if you want the best power supply around, Seasonic X-Series is the product you should buy.

Forgive me for going off topic. I will try to provide more assistance when bassport replies back.
 
Thanks for the numerous replies!

I got quite an expensive 850W (Thermaltake afaik) power supply which should be enough I think? ;)

The thing is: Now the computer crashes randomly and I suspect a faulty hard drive (already ordered a new one). And the power up problems persist (of course).

The strange thing with the power up problem is: I do NOT get any beeping or any kind of display output. It just sits there, fans spinning with the HD led on fulltime (no flickering of any kind). The slight clicking noise you hear after spin up of the hard drives is missing. They seem to spin up (at least one of the two does) but then this little crackle you hear after starting the PC is not there. I dunno if you know what I mean.

So: am I right in suspecting the hard drive and not the power supply? Because the power is there and the supply itself was a pretty decent one.

On the other hand: the hard drive should not be a problem before POST, should it? I mean the BIOS checks the SATA's only after the BIOS screen info appears, isn't that so?
 
The BIOS would post fine 100% of the time if it was a hard drive issue. Since your issue is an intermittent lack of posting, it is either related to the power supply or motherboard. Here's a solution: Go to your local electronics store and buy a PSU that is adequate enough to get your system to boot up. It doesn't need to be anything special, just make sure they'll allow you to return it after it's been opened. Hook it up to your system, and see if you have any issues booting up. If not, then it's probably your current PSU is failing. Otherwise, the issue is likely motherboard related.

Do keep in mind that Thermaltake PSU's are pretty average as far as power supplies go. They aren't great but they aren't horrible. I've had one die on me before, and it took out my motherboard with it.
 
Thanks for the numerous replies!

I got quite an expensive 850W (Thermaltake afaik) power supply which should be enough I think? ;)

The thing is: Now the computer crashes randomly and I suspect a faulty hard drive (already ordered a new one). And the power up problems persist (of course).

The strange thing with the power up problem is: I do NOT get any beeping or any kind of display output. It just sits there, fans spinning with the HD led on fulltime (no flickering of any kind). The slight clicking noise you hear after spin up of the hard drives is missing. They seem to spin up (at least one of the two does) but then this little crackle you hear after starting the PC is not there. I dunno if you know what I mean.

So: am I right in suspecting the hard drive and not the power supply? Because the power is there and the supply itself was a pretty decent one.

On the other hand: the hard drive should not be a problem before POST, should it? I mean the BIOS checks the SATA's only after the BIOS screen info appears, isn't that so?


Right. It should post, whether you have a hard drive connected or not.

The other thing is, are you sure your PC has a speaker? Most pre-built ones do... anyway, if you built it yourself, you should know.

Something about this seems familiar. I recall a PC doing this when the RAM was not completely inserted, causing a malfunction. This would cause the PC to beep if you have a speaker.

Do you have onboard video? Do you have both onboard and a video card? If so, try the other output and see if you get something to display. It happens.


EDIT:

I'm thinking it could be possible that any type of hardware malfunction could do this. Some things I have in mind are:

-Motherboard not grounded properly/fully; not on the standouts correctly.
-An adapter card (of any type) not seated properly or damaged
-HDD or HDD cable malfunction
-A stray particle (even a piece of hair) that conducts electricity causing a short somewhere. (believe me). If you have compressed air, that would be best.

In any case, you should unplug any device that isn't required for the PC to function for testing. For starters, unplug the Hard drives and try to boot up.
 
Shit, I just removed the RAM and I hear no beeping sound. I think I actually forgot that I don't have a speaker installed (Thx VirusType2 for the tip, btw). That's a bit embarassing...
 
OMFG, I just attached a speaker and... it doesn't bleep!!!!!!! It just sits there like before and does nothing most of the time (it beeps when it's booting properly).
 
It beeps to let you know it's booting properly. If there was an error it would play a sequence of beeps or not beep at all, as in your case. I'm gonna agree with Sedako, it's either your motherboard or your power supply.
 
OMFG, I just attached a speaker and... it doesn't bleep!!!!!!! It just sits there like before and does nothing most of the time (it beeps when it's booting properly).

I don't think anything is actually broken, because when this started, it was occasionally working. (1 out of 3 times, it worked, you said.) That's why I think it's a bad connection somewhere causing a malfunction.

Just follow through the list of suggestions I made in my last post, and I think you will figure it out.

Have you tried booting the computer without any adapters plugged in? Well, except for video, so you can see it post onscreen. [strike]You can even remove the RAM and it would still post so you can access the BIOS menu.[/strike]

So, if you've stripped it down and got only the PSU+motherboard+CPU+video, and it STILL doesn't post, then you know one of these things is the problem.

If it is still not working, then take it a step further. If you have a different video card (even if it's PCI or something) and a different PSU you could try, then do that.

One thing we didn't ask is how old all this stuff is. Capacitors don't last forever. The PSU, motherboard, and Video adapter all use capacitors.
 
It beeps to let you know it's booting properly. If there was an error it would play a sequence of beeps or not beep at all, as in your case. I'm gonna agree with Sedako, it's either your motherboard or your power supply.

Or your CPU.

At this point the best troubleshooting method is to disconnect everything you possibly can and listen to beeps. If you do that and no beeps occur you are sort of shit out of luck, could be the mobo, could be the cpu, or it can be the power supply (if its the power supply you can try another one).

If the computer is booting up from time to time back up all your stuff. I dont believe it's your hard drive, but since you have to turn on and off your computer when this happens constantly your hard drive can be damaged. You want to make sure you have a back up of the most important stuff to you.
 
Or your CPU.

At this point the best troubleshooting method is to disconnect everything you possibly can and listen to beeps. If you do that and no beeps occur you are sort of shit out of luck, could be the mobo, could be the cpu, or it can be the power supply (if its the power supply you can try another one).

It's likely not the CPU given the nature of issue, but that's easy to test. Once you get booted up, run something like prime95 or OCCT and stress the CPU.
 
I could be wrong but as far as I understand it the BIOS can not perform a POST until the CPU is initialized. The reason for this is that many hardware signals are routed through the CPU (especially when it comes to memory). So if your CPU isn't working no POST can take place and as a result you would get no beeps. I guess if anyone was bored enough and had a spare PC they could take out the CPU, turn it on, and see what happens. I have a spare PC but unfortuantely not quite bored enough.

Also, a stress test might not always find issues with a CPU that is not initializing properly. Once initialized everything will run fine even under stress. The problem is with the actual initializtion procedure.
 
While I would assume it won't post without a CPU (after all, a BIOS is just a ROM), I figured it should post without RAM, however, I've never tried it, and it may not be possible. So skip that troubleshooting step (booting without RAM) as I mentioned previously.

EDIT: A quick Google search has 3 people saying it won't be possible.
 
Thanks again for the replies.

I removed everything but the video card from the mobo and the problem still occurs. Even without RAM. The mobo does NOT POST when the RAM is not inserted. The really weird thing is that the problem stays exactly the same: Sometimes it beeped three times to signal that no RAM is connected and sometimes it just silently sits there and judges me.

So I figured I give the PSU a try. I'll get a Corsair TX750 and try that out (I can bring it back to the store, I asked them).

The components aren't that old (pretty much 2 years old).

I'm really suspicious of the mobo because it's the MSI P7N diamond (780i nVidia) which was expensive as f**k but seemed to be a little experimental (it got good reviews, but they were all a bit sceptical. Don't ask me why I bought it anyway... I wanted the latest and greatest I guess). I'll never buy such an expensive mobo again.

I may have to add: The problem occured since the beginning. It just gotten a lot worse over the years. Since I replaced the video card a few weeks ago I doubt it has something to do with that.

I'm building my own PC's since 15 years now and I never had any problems like this...
 
Yeah, it does sound like the motherboard is faulty, but I can't say for certain. It's possible it is still under warranty, but if I were you, I would contact MSI regardless. They seem to be very reasonable from what I hear. It's worth a shot, especially considering it's been doing that since you got it.

EDIT:
Sometimes it beeped three times to signal that no RAM is connected and sometimes it just silently sits there and judges me.
this does seem to point to a RAM problem though. This is with the RAM installed, right? It could still be the motherboard, and not the actual RAM sticks though. Like the slots or leads.

:shrug:

I'm assuming you tried one stick at a time (if your configuration supports single channel)?
 
this does seem to point to a RAM problem though. This is with the RAM installed, right? It could still be the motherboard, and not the actual RAM sticks though. Like the slots or leads.

No, it beeps because the RAM sticks were removed! So IF it actually initialises it seems to work fine all the way through, but it doesn't seem to get that far rather a lot.

I'll try getting a 750W Corsair TX750 and try it with that. Thanks for the replies. I'll get back to you with the results.

One last thing though: If it isn't the PSU and since I can't know for sure that it isn't the CPU OR the mobo, would it be worth it to get an i5? I mean I'd have to shell out quite a few bucks to get the same performance I had before (Quad Core 3.06 GHz), because I'd have to get a new mobo, CPU and RAM. Is it worth it or should I just get a cheap mobo and hope it isn't the CPU?

Regarding the warranty of the MSI mobo: I seem to still have Bring-In warranty till 2011, but I'm pretty sure I would have to wait at least 3 months before I get anything back from them which I don't want to. Or is it normally quickeR?
 
Regarding the warranty of the MSI mobo: I seem to still have Bring-In warranty till 2011, but I'm pretty sure I would have to wait at least 3 months before I get anything back from them which I don't want to. Or is it normally quickeR?

Warranty replacements have always been fairly quick for me from most companies. I usually get the part back within 2-3 weeks.
 
I've tested it with a new power supply and it's kinda the same. Although it's beeping ALWAYS now with the RAM removed (which is a good sign but very confusing considering). With the RAM inserted it is the same: Boot ups to the POST are quite rare.

Could it be the RAM?
 
As long as it's not doing the RAM beep code when the RAM is inserted, then I guess I would try re-seating the CPU, since that would just require some work and some thermal paste. Because, it won't post without the CPU either. I mean, it could just be some speck of shit on one pin or something. A slightly bad connection could in fact work sometimes, like you describe. That's experience gained from other areas, but I'd say it's worth a shot. Re-seating a CPU compared to buying a new PC and having to build the whole thing anyway.
 
Well... I tried the new PSU to no avail and got myself a Gigabyte mobo with a Phenom II 965 3.4 GHz Quad Core. I don't have that much money, but I had enough.

There were a lot of small things not working with the old system even after correctly booting up: Hibernate (took 5 minutes to wake up), audio jacks (switched between front and back outs all the time) and the BIOS was shit.

So yeah... I got a smoothly running Win7 now half the price I paid for the original (I'll never shell out more than 120-150$ max for a mainboard).

On top of that I got SATA3 and USB3... you never now.
 
So you should have nothing stopping you from RMA the old mainboard. Something tells me you won't.
 
So you should have nothing stopping you from RMA the old mainboard. Something tells me you won't.

Ah, I see what you did there. I might try to return it eventually... I actually might, my friend.

In all seriousness: It sounds like a good idea to try to get it exchanged.

Thanks for all the suggestions, you guys rock!
 
No problem man.

Here's the thing: you won't be able to RMA that board forever. There is a window. And who is to say you might not regret it or one day want or need a working board for your working [CPU/RAM].

Some people are good at dealing with things like this, but I'm not. I don't want to spend the time to think about it - that's the hard part. Is it worth it? What do I need to do? Who do I need to contact?

Anyway, just some encouragement/perspective
:cheers:
 
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