Been a while...diagnosing a non-powering PC

C

carl67lp

Supreme [H]ardness
Joined
Oct 17, 2001
Messages
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It's been a while since I've been around the forums...life got in the way. :) But I am certain it's still chock full of geniuses, so I'm here looking for help.

Backstory: I bought an Xbox (original), and planned to softmod it tonight (Ndure mod). I got my PC next to my Xbox near the TV, and was going to run one of the PSU's molex connectors to the Xbox HD, per the instructions.

So, I hooked that up, had my PC's hard drives disconnected, and attempted to boot my PC. Nothing--it refused to turn on. So I shifted it a bit, and suddenly it started to boot--then nothing.

I moved it to the floor so I could look at it (disconnected from the Xbox mind you), and saw nothing out of the ordinary--no obstructions to the CPU fan, nothing.

Then I moved on to regular diagnosis of the problem--disconnected everything and reconnected it (power cables and IDE cables) so that things were a bit neater and easier to see. No change. Then I disconnected all hard drives, again nothing. Disconnected the DVD-RW, nothing. Disconnected the case fans (but not the CPU fan), nothing. Finally I removed the only PCI card I've got, my sound card, and tried booting again. Guess what...nothing. I even reset the CMOS (jumper style--the battery is behind the video card fan) to no avail.

So essentially I'm sitting here with a PC that suddenly has developed a gremlin, and I have no idea how to fix it. I'm doubtful that hooking the molex up to the Xbox for a moment had anything to do with it, but who knows.

In any case, I've got a 450W PSU (Xclio I believe, about a year and a half old); an AMD 3600+ or somesuch, S939; and an Abit AV8-3rd Eye motherboard. If it matters, the case is the Antec Lanboy aluminum one.

Please help! I really need to get this fixed. :(
 
Have you tested the PSU? Disconnect all the cables and then short the green wire on the ATX connector to a black wire with a paper clip and see if the fan spins up.
 
Rabid Badger said:
Have you tested the PSU? Disconnect all the cables and then short the green wire on the ATX connector to a black wire with a paper clip and see if the fan spins up.
Click to expand...

Well there's my first-ever PSU test. :) Okay, tried that, and the fan does indeed spin up.

I think in my haste I forgot to mention that the computer would "boot" for about 5 seconds, then power down completely. This happened on each of my experiments. Unfortunately, I have no idea if anything came up on VGA, as I had it connected to my LCD TV (via a purchased-tonight cable) but nothing ever displayed.
 
If the PSU powers up then I'm thinking that the mobo could be the problem. Take it out of the case, leave it on a box and try to power up your PC like that. This rules out whether or not the case is shorting out the mobo.
 
Sounds to me like you've got a short somewhere. Something may have shifted while you were moving the machine around. Try pulling the motherboard out and booting the machine outside the case.

If that does the trick make sure none of the mounting points are out of position and touching traces on the motherboard and reinstall the components.

Edit: Beat to the punch.
 
I know this has already been said, but this copy and paste has a bit more detail...

Setup everything outside of the case, with the mobo on top of its cardboard box. Plug in only the essentials:
- PSU (namely: main 20/24-pin ATX connector and 4-pin ATX12V P4 CPU Connector)
- CPU w/ HSF
- Single stick of ram
- Videocard if there is no onboard video
- Monitor
- Keyboard
- Use a screwdriver if your board doesnt have an onboard power switch
- System speaker/buzzer

Jump the two power switch leads to turn the power on (with a screwdriver). If it won't post, try different RAM slots. If it won't post, pull out the ram (so no ram in the system) and listen for error beeps. If none, pull the vidcard and listen for error beeps. If none, re-seat the CPU/HSF and try again.

Also, try another PSU.
 
enginurd said:
I know this has already been said, but this copy and paste has a bit more detail...

Setup everything outside of the case, with the mobo on top of its cardboard box. Plug in only the essentials:
- PSU (namely: main 20/24-pin ATX connector and 4-pin ATX12V P4 CPU Connector)
- CPU w/ HSF
- Single stick of ram
- Videocard if there is no onboard video
- Monitor
- Keyboard
- Use a screwdriver if your board doesnt have an onboard power switch
- System speaker/buzzer

Jump the two power switch leads to turn the power on (with a screwdriver). If it won't post, try different RAM slots. If it won't post, pull out the ram (so no ram in the system) and listen for error beeps. If none, pull the vidcard and listen for error beeps. If none, re-seat the CPU/HSF and try again.

Also, try another PSU.
Click to expand...

I'll give this a go tonight when I get home from work. The only other PSU I've got is my wife's, and it's some generic 400 or 450W...but I suppose it'll at least let me try one other thing.

It's odd, but part of me wants the mobo to be bad, so I can have a (legitimate!) reason to upgrade. Unfortunately, we don't have the money to do what I'd want, so I fear it'd have to wait months for me to scrape the money together to do it right.

So let's keep our fingers crossed.
 
enginurd said:
When trying your wife's PSU, don't plug any drives in.
Click to expand...

Out of curiosity, why not? Its wattage rating is roughly the same as mine...so if that's the issue, then I'd be worried about running what I've got with my own PSU.
 
carl67lp said:
Out of curiosity, why not? Its wattage rating is roughly the same as mine...so if that's the issue, then I'd be worried about running what I've got with my own PSU.
Click to expand...

Because you want the PC to power on, first. Powering up is one of the most stressful times for a PSU because all components are hitting it up for power simultaneously. A lesser load on the PSU will give you a better chance of powering up the computer for POST.
 
enginurd said:
Because you want the PC to power on, first. Powering up is one of the most stressful times for a PSU because all components are hitting it up for power simultaneously. A lesser load on the PSU will give you a better chance of powering up the computer for POST.
Click to expand...

Right right right... Of course. :) How silly of me! (You can tell it's been a while since I've done tech support-type work, now that I've finally moved to the Web field full-time.)
 
I finally got the chance to do some work on it tonight. I took everything out of the case, and set the motherboard on a piece of cardboard on my desk. The only thing connected was the video card, two sticks of RAM, the CPU (of course), and the PSU (20 pin plus the ATX header or whatever it's called).

Tapped the screwdriver to the power headers, and the same thing that'd been happening, happened again--power for about 5 seconds, several changes on the LED display, then nothing. Same thing with the video card removed, and same thing with one or two RAM sticks removed.

So there you go. Looks like I'm up the creek without a paddle.

Please tell me there's something else I can try. I literally wouldn't be able to replace this for a year or more.
 
have you tried a different video card, ram?

i had a similar issue when i upgrade my rig to use a ocz powerstream psu as my 9800pro would cause it to flash and then die, swapped video cards everything was peachy

the only thing i could figure was that the video card was either overvolting or undervolting causing the power supply to shut down
 
This is with both PSUs, correct? If so, it looks the mobo could be the problem.
 
I do not have a different video card to test with (I don't think, anyway...my wife's is PCI-E and the really old video card I have is, I think, PCI). I also don't have any other RAM, again aside from my wife's. But it shouldn't matter, I'd think, given that the system did the same thing without either of those components, as it did with them.

I haven't tried the other PSU, but given that my own seemed to work (when shorting green/black), I didn't think it would be necessary. I guess I can try and yank my wife's PSU out of her computer in the morning, but I don't hold out any hope.

Did I mention how absolutely upset I am?
 
Definately try it with the other PSU. Try it with a single stick of ram instead of 2. Also, make sure you have a system speaker plugged in, so you can hear the error beeps, if there are any. Do you hear any error beeps without ram? do you hear any error beeps without the vidcard? If no to both of those, its the board.
 
enginurd said:
Definately try it with the other PSU. Try it with a single stick of ram instead of 2. Also, make sure you have a system speaker plugged in, so you can hear the error beeps, if there are any. Do you hear any error beeps without ram? do you hear any error beeps without the vidcard? If no to both of those, its the board.
Click to expand...

Well, good news and neutral news...and some bad news. The good news is that my wife's PSU isn't a generic POS (it's a Thermaltake...not the best, but at least not a "Jim-Bob's PS-You) and when I connected it to my mobo and start it up, it doesn't shut down on me.

The neutral news is that I don't get any video either. The fan on the video card starts up and spins normally (it's an Arctic Cooler or somesuch) but no signal. I don't have easy access to a speaker so I don't know if there are any crazy beeps.

In any case, I'm going to clear the CMOS completely, and do some further testing (i.e., remove the video card to see if the onboard POST code LEDs say anything different; try a single stick of RAM; and so on). In the meantime, anyone have any suggestions? Incidentally, the POST code is something like 4.0. or 4.C. (I don't remember which), but the AV8 manual I downloaded doesn't indicate anything relevant.

Oh, and the bad news? I grabbed my wife's case by the (empty) blowhole at the top, trying to put it up on the balcony railing outside to dust it out, and promptly sliced my left index finger something fierce. Not enough for stitches of course, but enough to sting. I've been re-christened. :D
 
Alright, that was quick... I went back right after I posted my note above, and tried again with one stick of RAM. Wouldn't you know it, but it worked, video and all (although, of course, I got a CMOS checksum error, but that was expected).

I stuck the RAM back in, booted up a second time, and again things powered on fine.

So it looks like the PSU might have been the culprit all along (although I intend to try the old one once more, just to be sure).

I'm pleased that it's not the motherboard, for sure; we just bought a dSLR and can't afford anything else! (Which means, sadly, that the replacement PSU will have to wait a month or two as well...unless someone has a 500W+ just lying around. ;))

Thanks, all, for your help.
 
I'm sorry for hijacking your thread, but I thought I'd post here since I'm getting the same problem.

One second, my computer was running fine. Went and cleaned up some of my wires, unplugged the psu, usb, monitor and keyboard cables, straightened it all out and plugged it all back in. Now there computer won't start.

I see a green LED on the motherboard and when I unplug the power and wait a few seconds and plug it back in, the fan spins for a second and the green LED lights up. But pressing the power switch does nothing.

After reading this thread, I unplugged all the components except for the ATX (20 pin) on the motherboard and still no signs of life. I hear you mention about shorting the ATX with a paperclip, how do I do that to test if it's my PSU or if it's something else?

I'm really hoping it's just the PSU and nothing more serious.

Thanks.
 
iqwertyi said:
After reading this thread, I unplugged all the components except for the ATX (20 pin) on the motherboard and still no signs of life. I hear you mention about shorting the ATX with a paperclip, how do I do that to test if it's my PSU or if it's something else?
.
Click to expand...

Use a paperclip and connect the green wire/pin to a black wire/pin. That should start up the PSU.

Also, are you sure that the CPU and HSF is in correctly? Also, are you sure that you wired up everything correctly?
 
Just to be sure.

Nothing will be connected to the PSU.
Then Place a paperclip on the green and (ANY) black wire on the 20 pin ATX.
I'm guessing I power up the PSU by plugging it in and the switch on the back and this should start the fan on the PSU?

Thanks.
Just making sure I don't make things worst than they already are.
And also, I'm quite positive all connections were correct before it died.

EDIT:

Ok, just did the short test and the fan does work/spin,

What's next on the process of elimination?
 
carl67lp said:
It's been more than a year, so it's probably out of warranty.

Thanks for the suggestion--I'll keep it in mind!
Click to expand...

Double check the warranty. Some PSUs have 3yrs. Some have more, some have less... but you get the idea.

I second the XClio recommendation. However, if you have a higher budget, go for the Stablepower (rebadged Enhance instead of CWT) or a Corsair branded (built by Seasonic) PSU instead.

iqwertyi said:
What's next on the process of elimination?
Click to expand...

Start your own thread. Then try powering up with just the bare essentials plugged in.

enginurd said:
I know this has already been said, but this copy and paste has a bit more detail...

Setup everything outside of the case, with the mobo on top of its cardboard box. Plug in only the essentials:
- PSU (namely: main 20/24-pin ATX connector and 4-pin ATX12V P4 CPU Connector)
- CPU w/ HSF
- Single stick of ram
- Videocard if there is no onboard video
- Monitor
- Keyboard
- Use a screwdriver if your board doesnt have an onboard power switch
- System speaker/buzzer

Jump the two power switch leads to turn the power on (with a screwdriver). If it won't post, try different RAM slots. If it won't post, pull out the ram (so no ram in the system) and listen for error beeps. If none, pull the vidcard and listen for error beeps. If none, re-seat the CPU/HSF and try again.

Also, try another PSU.
Click to expand...
 
enginurd said:
Double check the warranty. Some PSUs have 3yrs. Some have more, some have less... but you get the idea.

I second the XClio recommendation. However, if you have a higher budget, go for the Stablepower (rebadged Enhance instead of CWT) or a Corsair branded (built by Seasonic) PSU instead.
Click to expand...

The dead PSU I've got is actually an XClio. Looks like it was mfg in 2005--May to be precise. I don't have any of the paperwork so I have no idea if it's under warranty. I guess a trip to their Web site is in order!
 
carl67lp said:
The dead PSU I've got is actually an XClio. Looks like it was mfg in 2005--May to be precise. I don't have any of the paperwork so I have no idea if it's under warranty. I guess a trip to their Web site is in order!
Click to expand...

So it's confirmed dead? Did you re-test it with the reseated RAM? If so we may have discovered the life expectancy of the Fuhjyyu capped Xclios.
 
carl67lp said:
The dead PSU I've got is actually an XClio. Looks like it was mfg in 2005--May to be precise. I don't have any of the paperwork so I have no idea if it's under warranty. I guess a trip to their Web site is in order!
Click to expand...

The 450BL is a CWT built unit. How hot is your room where the PSU is? Low end CWTs are known to use fuhjyyu caps, which can't take much heat. Though, I'm not sure if thats your PSU's problem or not, but I'm just curious.
 
Confirmed dead. We live in Arizona now, so the heat's definitely an issue...and it probably didn't get enough ventilation.

Odd, though, that it chose to die when I took it to the living room...

In any case, yes, it's dead. Anyone need a paperweight? ;)
 
carl67lp said:
Confirmed dead. We live in Arizona now, so the heat's definitely an issue...and it probably didn't get enough ventilation.

Odd, though, that it chose to die when I took it to the living room...

In any case, yes, it's dead. Anyone need a paperweight? ;)
Click to expand...

Heh, yah, don't get another CWT built unit unless its higher end. Go with the Stablepower if you want to stick with XClio. The alternative is the Enhance 5150GH. Other good options are the Corsair VX and HX series, Antec Earthwatts and True Power Trio lines.

RMA it if you can, and sell the replacement eBay... or in fact, pm me, lol. Or better yet, keep it as a spare.
 
enginurd said:
Heh, yah, don't get another CWT built unit unless its higher end. Go with the Stablepower if you want to stick with XClio. The alternative is the Enhance 5150GH. Other good options are the Corsair VX and HX series, Antec Earthwatts and True Power Trio lines.

RMA it if you can, and sell the replacement eBay... or in fact, pm me, lol. Or better yet, keep it as a spare.
Click to expand...

I can't find anything on XClio's Web site about a warranty. I suspect I could email them, but I don't know if it'd be all worth it. But hey, if you want to buy it from me, let me know. :D
 
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