Power supply issue or something deeper? PC no start. Details within.

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Evil Llama

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Jun 1, 2013
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This may be something that is written somewhere else in the forum and I did not understand what I was reading. I am not really a "computer guy"... I am a parts changer and pretty good at using and understanding things I take apart. That said, I have a computer that is i pieces all over the study and I am determined to figure out what is wrong with it.

The system was working perfectly. Quick, responsive, the perfect home office computer. Then one day... When I push the power button, I get the blue "power" led in the front, but nothing else seems to happen. My display stays in sleep mode, there are no indications that the hard drive is being accessed, pressing keys, such as putting my hand across the keyboard and pressing everything I can repeatedly to cause a full buffer "beep" does not produce a sound.

Originally I was thinking it was the display adapter, but even swapping it out with another one didn't change anything (hence the hand over every key thing listed above). I have been working on this for a while, and I read in other forum posts that my symptoms may be caused by the power supply, so I searched for a way to test the power supply... I think. Here is what I did:

I first grounded pin 15 and 16 to one another, then using a multi-meter, I put the neg. probe into pin 24, then I put the positive probe into slots 1-14, 17-19, and 21-23 recording the voltage. Here are the readings from 1-24 (forward slash means there was no power or ground)

1: +3.4
2: +3.4
3: /
4: +4.9
5: /
6: +4.9
7: /
8: +4.9
9: +5.1
10: +12.2
11: +12.2
12: +3.4
13: +3.4
14: -10.2
15: Connected to 16
16: Connected to 15
17: /
18: /
19: /
20: N/A No lead
21: +4.9
22: +4.9
23: +4.9
24: Used as ground

From what I can see, a variance of up to 10% is acceptable with the 400w power unit. By my math, pin 14 is out of spec. But pin 14, being a negative voltage, is used for integrated LAN but not much else. So could this be the issue?

Hardware:
Power supply Dynex dx-400wps
Motherboard ASRock 4CoreDual-VSTA
Video Card GeForce FX5200

If you need to know what other hardware the computer has, I can track down the model numbers for you.
 
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Dark Lord of Tech

Dark Lord of Tech

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Aug 18, 2009
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That is a very very poor PSU.

Tier 5 - Other than the units listed above for any of these brands, NOT RECOMMENDED. Replace ASAP if you have one.

A-TOP Technology
Apevia
APEX (SUPERCASE/ALLIED)
Aspire(Turbo Case)
ATADC
Athena Power
ATRIX
Broadway Com Corp
Coolmax
Deer
Diablotek
Dynapower USA
Dynex :bounce:
EagleTech
FOXCONN
FSP Everest
HEC Orion
Hiper Type-R
Huntkey
I-Star Computer Co. Ltd
In Win
JPAC COMPUTER
Just PC
Kingwin Inc.
Linkworld Electronics
Logisys Computer
MGE
MSI
NMEDIAPC
Norwood Micro/ CompUSA
NorthQ
NZXT
Okia
Powmax
Q-Tec
Raidmax
Rocketfish
Rosewill
SFC
Shuttle
Skyhawk
Spire Coolers
Star Micro
STARTECH
Thermaltake Purepower NP
Thermaltake Purepower RU
Thermaltake TR2 (and TR2-RX)
TOPOWER TOP
Ultra X-Connect
Ultra X2 >greater than 700 watt
Ultra LSP
Wintech
XION
YoungYear
Zebronics
 
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Hayden Hutsell

Hayden Hutsell

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If your computer wont even turn on, its probably the psu (more experienced people correct me if im wrong. What i would personally do is: Try a different wall plugin, different wall socket, make sure all of the cords are plugged in internally, then, if I was desperate and couldnt buy another psu, i would take it out and plug in an hdd or something else, so only one device is being powered to confirm it was not defective. Then, i would buy a new psu.
 
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Karadjgne

Karadjgne

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Dec 26, 2012
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Since the pc is already in pieces, I'd say breadboard it. Mobo on cardboard, cpu, cpu fan, 2x psu connectors for mobo, speaker and 1 stick of ram. If you still get no post beep, try other ram. It would be best if you had access to another psu, any will work if it's an ATX.

If you do get a beep, start adding components 1 at a time, listening for post each time. If you can fully build a pc this way out of case, chances are the stupid power button is the culprit (personal experience hah)
 
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Evil Llama

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Jun 1, 2013
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I understand that you are saying that the PSU is not a good PSU and I believe you are telling me that the PSU is not producing the proper voltage. Would I be correct on both accounts or just one? RE: other brands and list below (deleted for space), did you mean the ones listed chronologically prior or after the dynex on your list? TIA


It turns on, but it does not reach POST.


All your above suggestions (except buying a PSU as I am still in testing mode) have been done. The hard drive was put into the computer I am using now because I need the information on the drive(s) for my business. Thus the only items I am unsure of are the 3 I listed. Everything else is being used currently on the computer that I am typing on.

Does that clear it up a bit? I am sorry I was not as clear in my first post. Sometimes I overlook the details when I ask questions.


WHOOOOOWWWW COYBOY! You lost me at breadboard. In the above, I do not understand "Breadboard" or "Mobo on cardboard". I didn't list the Intel that I am using in the case, but is that what you are referring to when you say cpu? If so, my goal is to get the computer running. Upgrading is going to be done on a different system at a later time. It has not even met the "to-do" list. ;)

I tried one stick of ram, then tried the other. No change. Both sticks of ram are now the computer I am currently using. Both (seem) to perform as they should as this computer does not have any errors in post or start-up. As for the PSU, are you saying any old PSU could be swapped in to test the computer? I have not thought to do this because all my other computers have P4 single cores and no hardware upgrades (work computers). I was afraid of under-powering the system and breaking it further.


There is an issue with the power button as one of the detentes is broken. To bypass this, I removed the face and manually press the analog switch (bypassing the button).
 
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Hayden Hutsell

Hayden Hutsell

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So will your psu power lets say, JUST a hdd? Nothing else, just an hdd. I think you will honestly need to buy a better brand of psu. Blackbirds list is from a different thread ranking psu's I believe, Tier 1 being best.
I think you should just stop wasting your time on it, and just buy a more high quality one like antec, xfx, seasonic.
 
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Evil Llama

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Thank you Hayden. Hopefully this gets me a bit closer to understand what is going on. :)

The PSU can power just a hard drive. I can plug in a hard drive, turn on the PSU and it spins up. Also, I can use the PSU to spin it up AND access the information on the HDD. Using a laptop and cable it does not spin up, but laptop, cable, and suspect PSU it spins up and I can see the info on the drive.

I agree with buying a new PSU, and that is what I am trying to do. It is only 40-60 buck for the PSU and I have no issue with that. I guess to better explain, what I have an issue with is that I am not sure if that PSU CAN cause the issue with it not reaching post. Could a failure of a graphics card also cause it to not hit post? I know the mother board (obviously) would cause this issue if it was bad. I was kind of looking for a "Yes, this part is failing because .... and that could be the reason" so that I understand what is happening the next time I see a problem like this and do not have to ask again. I can just test it, know, and fix it.

As far as the tiers he lists, I do not see where the tier listing is, so what I was asking is where on his list should I be looking, the bottom or the top? As I said, I would happily swap out that PSU be it good or bad. I would still like to know if the readings show it as bad so I know what to look for in the future.

Also, What in the world is a breadboard or a Mobo on cardboard? I still find those as interesting terms. :)
 
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Karadjgne

Karadjgne

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Breadboarding is the term used when you pull every component out of the case, putting the motherboard on a flat piece of cardboard for protection, and installing bare minimums, that being 1 stick of ram, cpu, cpu cooler + fan, the speaker and the psu's 2x motherboard power connectors. The basis for doing this is to eliminate any possible hardware malfunctions. This means no hdd, no keyboards, no mouse, no gpu, no extras whatsoever. What you are wanting is just the beep that announces post (Power On Self Test). If when jumpering the psu you get a beep, then you can tell that those particular components are good. Then you start adding components 1 at a time, rebooting between each, building the pc outside of the case, listening for beep each time. As soon as you fail to get a post beep, remove the last component installed and reboot. You should get your beep.

The failure to post is therefore caused by that last item added. It can be anything. I have seen failures due to a bad cord on a monitor, bad keyboard cable, once even a bad USB mouse. What they did was short out, and cause the overvoltage/overcurrent protections built in the psu to kick in, causing the psu to shut down to prevent further damage.

I've also personally had a power on button fail on me, it lit up, but did nothing to start the pc.

If the breadboarding fails at the very beginning, the you know it's either the cpu, that 1 stick of ram (easily switched out to test with the other stick), the motherboard or the psu. If you have access to any other psu, and it passes post, the you know the psu is faulty. If it fails still then it's down to the cpu or motherboard, and 9/10 times its not the cpu.

Considering the quality of your psu, I'd have to say it's a good probability that that is the culprit. What most fail to understand is that the psu is the single most important component in any pc, it directly touches every component and has the very real potential to totally fry anything. This is where the tiers come from. They are a measure of quality, tier 1 being the best, tier 5 being the worst possible. Quality is not only measured by how well the psu is built or designed, but also on how well it performs for the rated outputs, how good are the components like transistors and capacitors etc, how well it controls heat and other things, so to make tier 1, the psu is practically bulletproof. There are more than a few YouTube videos of tier 5 psus actually catching on fire and blowing smoke and sparks. Tier 5 psus are literally ticking time bombs, its not a matter of if they will blow up, but when. And you own one. Tier 3 and higher are the only acceptable replacements, with tier 2B being a recommended minimum.
 
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Evil Llama

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Jun 1, 2013
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Sorry for letting this sit so long, but I think I figured out what is wrong here. I would enjoy a little input as to if I am on the right track.

After trying the breadboard with mixed results (It beeped the first few times, didn't beep on another try, then continued to beep when powered on), I tried swapping the various parts into another computer. Every part was able to be swapped into another case except the motherboard and the CPU.

All parts work in the other case (PSU, GPU, Sound card, etc.). I found that the fan on the GPU was not working and the card was quite warm, so I swapped the fan with another one that was laying around and tried again. Everything (including the new fan) worked perfect and the card stayed cool. I then decided to put everything back on the suspect motherboard and started it again. The fan on the GPU did not start. I moved the GPU to the other (known good) case and it worked perfectly. I moved it back to the suspect board and the GPU fan did not work.

Confused, I tried moving a sound card (with fan) around on different slots until I had tested each (white in color) slot on the suspect board. Every slot turned the fan on every time I powered up the system. The PSU and CPU fans turned on each time I powered it on. I was unable to test the purple slot (I think it is a graphics slot for a different type of connector), but the brown slot for my graphics card does not seem to power on the fan of the card.

Also, as my HDD is so quiet and I am getting older... hearing loss... I took a very oll and noisy HDD and put it in the suspect case and tried turning it on. The motherboard did access the noisy HDD and it sounded like it was reading the drive. I do not know what that means, but I thought it was important to note.

To me it seems obvious that the motherboard is failing somehow, but is it normal for a slot to fail? I have never heard of a single slot failing like this. Could it be that the graphics card got too hot when the fan was not working an somehow killed the slot for it? Yes, I think have to replace the MB, but I am curious about this one slot not working. Also, am I still on the right track?

Thank you again!
 
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