PC won't switch on - not sure if it's a power issues

Eklipze3k

Eklipze3k

New Member
PC won't switch on - not sure if it's a power issue

Long story so bear with me! :)

My partner has a Dell inspiron which she's had for a couple of years. I recently installed my old nVidia 8500GT and it's been running fine until 2 days ago when it kept crashing whilst playing a game (WoW). The monitor was saying 'no signal' and at first I assumed it was a cabling issue but whatever it was was definitely hanging the system. The monitor cable was swapped for a new one TNA, and the 8500GT was removed and the onboard graphics were tested (with setting turned down accordingly), again TNA.
The standard PSU in the Dell was only 300W so on the assumption that this was not up to the task of running the 8500GT, we've just gone and bought a 570W PSU and I've also re-installed Win7 on there.
Now we have a new issue where - if the PC is shut down normally - it doesn't fire up using the button on the front. It flicks the fans for a split second and LED in the mouse lights up momentarily but the PC doesn't start. I've used my multimeter and done a test of all the PSU pins by shorting pins 15 and 16 and testing the voltages are all within tolerance so I'm 99.9% certain the PSU is not at fault.
My concern now is that this leaves me with a motherboard fault, and of course the PC is out of warranty from Dell now. Would you all agree, or does anyone have any other suggestions of things I could try?
As before, I tried both with and without the 8500GT installed (the onboard GFX chip is an Intel G31/G33 I believe).
Incidentally, I do have a spare power button but haven't tested this yet as - following the PSU tests the PC booted successfully, but I wanted to see how successful this was so I shut it down again and of course it won't fire.

Many thanks
 
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I know you have a spare power button, but you could also remove the case power switch and carefully short the pins on the mobo header instead.

I've read that this could also be caused by a bad CPU. Do you have a spare mobo or CPU that you can use to test?

From my own experience, when this happens, the PSU is usually the first thing to check, but apparently it's okay. So there might be a short somewhere (are all the standoffs installed correctly?).

I had a dell desktop, and there was a switch on the side of the case (very strange) that caused the PC to turn on for 3 seconds then shut down (I have no idea what the switch was for, all it seemed to do was prevent the PC from starting up once you open up the case).

I also found this guide, it might help.
 
Thanks for the reply, I'll add my responses inline. :)
Twinbird24 said:
I know you have a spare power button, but you could also remove the case power switch and carefully short the pins on the mobo header instead.
Click to expand...

Tried that, does the same flickering for a split second but not firing - i'd compare it to a dodgy starter in a car where you can hear it turning but not firing the spark plugs.

Twinbird24 said:
I've read that this could also be caused by a bad CPU. Do you have a spare mobo or CPU that you can use to test?
Click to expand...

I have my own PC but I run and AMD set up, the Dell is Intel.

Twinbird24 said:
From my own experience, when this happens, the PSU is usually the first thing to check, but apparently it's okay. So there might be a short somewhere (are all the standoffs installed correctly?).
Click to expand...

None of the standoffs have been touched/adjusted since the machine left the factory so I have no reason to believe they could have become compromised.

Twinbird24 said:
I had a dell desktop, and there was a switch on the side of the case (very strange) that caused the PC to turn on for 3 seconds then shut down (I have no idea what the switch was for, all it seemed to do was prevent the PC from starting up once you open up the case).
Click to expand...

No case switch on this one :(

Twinbird24 said:
I also found this guide, it might help.
Click to expand...

I'll look over that just now, thanks :)

FYI - It's running now with the normal case switch used to turn it on. I'm personally leaning towards the mobo needing replaced (though how it could have become damaged I'm at a loss). I've not tried yet but I can almost guarantee if we try to fire up WoW it'll do the current trick of allowing us to log in, and then BSOD'ing, which then stops boot-up and we're back to square 1 :o
 
No idea, it disappeared too quickly and event viewer has nowt useful in it at all just that "The previous system shutdown at xxxxx was unexpected" followed by "The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed or lost power unexpectedly."

Edit: Just tried running WoW and it seems to have stopped crashing the system, which is a good start. But I'm still concerned that when we shut down, come the morning it won't boot up again and we'll be back to square one. We're also still running with the onboard GFX chip, and I do want to install the 8500GT or order something better so my question really now I guess (and posting this in PSU section seems a bit daft now) - do you agree that getting a new motherboard (probably this one) would be a good idea and the most likely way of solving the issue?
 
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I'm just not sure if it's a motherboard problem. You can disable automatic restart, so if another BSOD appears, it won't go away quickly. Maybe the the PC is overheating when playing WoW, download hmonitor or SpeedFan and see what happens to your temps when playing WoW.
Hopefully some other forum members will also add their opinion.
 
Have you checked the mobo caps for the "Capacitor Problem" ? Thats always a good idea. Also for what it is worth some mobos won't boot if the mobo battery is dying. Not very expensive to replace that.
 
Some PCs also won't boot because the CPU fan is not working, probably not the problem here, but it's worth checking if the other suggestions don't help.
Just to clarify, does your PC not boot up at all or does it boot up and then turn off again after about 3 seconds?
 
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JHM said:
Have you checked the mobo caps for the "Capacitor Problem" ? Thats always a good idea. Also for what it is worth some mobos won't boot if the mobo battery is dying. Not very expensive to replace that.
Click to expand...

Can you clarify this for me please? I'm at work just now so my internet access is pretty limited.

I haven't checked the battery, though I did reset the CMOS, as you say another battery is cheap enough so a good suggestion, thanks :)

@Twinbird24: When it fails to boot, upon pressing the Power Switch, the lights and fan flick for a split second but it's nowhere near as long as 3 seconds, not even 1 second. Annoyingly though, I've just tried it this morning before I left the house and it booted up first time no problem.
 
K, The long and short of it is that somebody stole a formula for capacitor electrolyte from Sony some years ago and sold it to a company that manufactured electrolyte for capacitor manufacturers. Said formula, however, was missing, (for security purposes), one vital ingredient among the several that are used to prevent the breakdown of the electrolyte into gases when electricity is passed through it.

You may remember from high school that if electricity is passed through water, it breaks down into hydrogen and oxygen.

Anyway the company that bought the formula, started manufacturing it and selling defective electrolyte to capacitor manufacturers. Because only one ingredient was missing, it took quite a while for the caps made with it to fail, (about 4 years on a used FIC VA 503+ that I built into a machine). Further since no capacitor manufacturer was keeping records of whose electrolyte went into which batch of capacitors, it was years before suspicion finally focused on a Taiwanese company.

The net result was that for years mobo manufacturers were using some capacitors that were failure prone over a period of time. The failure shows up visibly when the caps start to bulge at the top, because the electrolyte inside them is breaking down into gases.

I will try to see if Steve has a bad cap board he can lend me to take pics of to show you what to look for.

EDIT : That proved not to be necessary, as I was able to browse another computer site I go to and find this photo. These are BAD caps pulled and replaced by "Tazwegion" in Australia.

may2002enl.jpg
 
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If there was a 'Thanks' button I'd click it :)
I'll look at them when I get home and check them out, as I said in the first post the PC is 2 years old and has only just started acting up, would that be long enough for this fault to become apparent or - more to the point - when was the issue realised and cap production methods changed to eliminate the problem?
 
Checked caps, all ok, just running a test now with the old PSU, in case the new one is faulty (despite testing OK).
 
I'm sure the new power supply is fine (but there's nothing wrong with testing it just to make sure), the old one may not give you enough power for the graphics card you plan on putting in your system though.

Did you make sure the CPU fan is working properly?
I agree with changing the BIOS battery, may not be the problem but those things are pretty cheap to buy.

Check your temps like I mentioned early, it could be that your PC is overheating.

I think that there is a short circuit somewhere on your motherboard that is causing this problem (maybe a loose screw somewhere that isn't supposed to be there) or maybe there is a malfunctioning component that is causing the short circuit. If the PSU tests okay and all our other suggestions don't help, then replacing the motherboard may fix this (but only if the other suggestions don't help, could possible also be the CPU, but not quite sure).
 
K, another thing you can check is your RAM. This machine I am using right now came with RAM that was slightly defective in the sense that it would not work properly when set at the "De Fault" timings. This is particularly true when RAM of this sort is being "Stressed", - i.e. gaming; - resulting in programs saying they had encountered a problem and must close, crashes, BSODs, boots into black screens, etc.

Running memtest on it generated 57 memory errors in one pass with the RAM set at its "De Fault" timings, and the voltage set at its "De Fault" voltage.

Changing the "De Fault" voltage by bumping it up .1v. resulted in the number of errors being reduced by about 1/2 but did not solve the problem Resetting the voltage to its "De Fault" and changing the RAM "De Fault" timings from : 5, 5, 5, 18, 3, 3, - to - : 6, 5, 5, 18, 3, 3, DID solve the problem and the machine was able to run Memtest error free for over 19 hours. I subsequently RMA ed the RAM as defective.

That RAM was "Buffalo Select DDR2 800 MHz RAM". Yours will probably be different, but if you experiment with the settings, particularly by raising the first value by 1, you may find that solves your problem.

Re When was the "capacitor problem" solved, I am not sure; I avoid it by buying Mobos with solid state caps instead of electrolytics. Gary Headlee, The : [email protected] could probably answer that question.
 
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Ok, here's the latest.
The original WoW crashing issue has been traced to an issue with one of Carrie's characters as it loads and runs fine with all of the others (it never occured to us before yesterday to try any others!).
With the original PSU I have no problems at all - yet to test the GFX card with it but suffice it to say, it shuts down, boots up and does everything a PC should do on the button every time. As soon as we try the new PSU, we're back to the flicking lights, and not booting.
Now I know what you're thinking, duff PSU right?
Took it back to Maplin to get it swapped out - they tested it (pretty much by just shorting pins 15 & 16) and it ran fine so they're adamant that the PSU is ok. However, they did suggest to me that Dell use their own proprietary pin layout, as opposed to non standard ATX. This sounded plausible as they'll want you to spend 2x as much on their own stuff, rather than go to Abdul down the road for a couple of quid.
Everything I find about Dell's own power supply system though seems to relate to the old 20-pin connections though, as opposed to the new 24-pin system. So the new question is - does anyone know if Dell still use a proprietary system, do you know if an adaptor cable is available (searched ebay TNA) or do we still think the PSU is b0rked?
 
I found an adapter here, only $14.95.

From website:
"The reason you need a proprietary Dell power supply is because Dell has been using specially modified ATX motherboards with non-standard pinout of the motherboard power connectors. This Dell to ATX adapter converts between the non-standard pinout to the standard ATX pinout and turns a standard ATX power supply into the equivalent of a Dell power supply."

So it seems it could have been the power supply after all :rolleyes:

I'm not sure if Dell still uses proprietary parts (like mobo/ PSU), but according to this 2008 blog post, they are stopping this.
 
You should be able to download the mobo manual from Dell's website; and said manual SHOULD have detailed diagrams of the main PSU plug specifying the function of each wire position. Given that, you could then compare it to any standard manual for an ATX board, and compare which wires do what and where they are connected. That would enable you to reshuffle the wires on a standard supply to comply with Dell's proprietary IDIOCY.

Why Dell comic books hasn't sued Dell computer for the use of the name is beyond me. Dell's are supposed to be funny, not an ongoing "PITA".
 
I found that adaptor too TB24, but it's old style 20+6 as opposed to 24pin atx, I'm going to compare the pins on the 2 connectors tonight using the multimeter if I can't find a pin diagram from Dell. I did think it would be a case of just reshuffling but according to another blog I found a while ago, the pins are quite different on the 20+6 so it involves cutting and splicing, not so much fun if that's still the case for the 24-pin :(

Edit: BTW, thanks for the all the input guys, really appreciate it :)
 
Sorry if this comes across as rude msgplacide, but did you read the whole thread? The Dell PC works perfectly fine with it's own OEM PSU, but won't boot reliably with a standard ATX PSU. I've now tested this PSU in my own machine and it works fine (much to my chagrin) so - it's not a memory issue (although, FYI, I did take all the modules out and reseat them just in case), it's not a motherboard issue as it works perfectly well with the OEM PSU, it's not a power switch issue as it works perfectly well with the OEM PSU, all it is put quite simply is a Dell issue whereby they can't do things the way the rest of the world does and insist on having proprietary crap and charging double the retail value if you want to change anything :(
From suggestions elsewhere (a Fiat forum of all things, would you believe!) we found an adaptor cable that would work but shipping from LA to the UK, plus the cost of the power supply we already bought makes it more financially sensible to return the PSU and get a new motherboard and PSU elsewhere for less than £2 more than we would have paid for just the PSU and adaptor cable.

Again though, I want to thank everyone for all of their suggestions and input, it's much appreciated :)
 
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