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Custom Computer Refuses to POST


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#1
Diarmaid

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Please read all of this post before replying (I dislike people suggesting things I've already done)

I decided as a summer project to build a computer from scratch, just for the heck of it. Obviously there was a problem with this (other wise I wouldn't be asking for help). So here's the situation: when ever I plug in the computer to the wall, the keyboard lights up along with a few spinning fans, but this is just it doing a test I believe. When ever I hit the power button though, all [bleep] breaks loose. The case lights up, all of the fans start spinning, and the monitor goes to sleep(monitor sleeps when plugged in to either video card or onboard VGA(all attempts to get video were made on them both)). The keyboard gives me no response to anything I do either. There are no beeps, there is simply nothing but a whole lot of noise from the fans. And after about 5 seconds it shuts down (as if over heating or not enough power)

Specs:
11-Bay ATX Window Computer Case w/480W power supply (Alienware design)
CenDyne 2GB DDR2 RAM x2
MSI G31M3-L V2 iG31 Socket 775 mATX motherboard
54Mbps 802.11g Wireless LAN PCI Adapter
Intel Pentium 4 3.0GHz 800MHz 1MB Socket
AOpen GeForce 8500GT 512MB DDR2 PCI
TV-ATSC ATSC/NTSC PCI TV Tuner Capture Card
Samsung SATA HDD 500GB
Seagate 200GB IDE HDD
Sony DVD Drives x2

My attempted solutions: I replaced the power supply because I figured, if it's not enough power or a faulty supply, might as well replace it right? So i replaced the 480w power supply that came with the alienware case with a 600w coolmax. I got no change. Then i realized that my motherboard has no fans plugged directly into it, they all use a molex connector. Perhaps it really does think it's overheating. So i ran into my storage room of old computers (aka my bed room) and grabbed a few compatible fans to plug into the board. I started it up with a fan plugged into sysfan1 and it ran for 10 minutes before i decided it wasn't going to shut down on me. I got all excited that my computer was finally working that i decided "Hey, maybe I fooled it long enough to figure out that the fans are fine." I unplugged the fans and attached the molex fans to the power supply and tried to turn it on. I had it running for a good 3 hours because i got distracted by a Stargate marathon. It was running good without shutting down or getting hot. I hooked it up to the monitor and the tears began to roll. Still no screen. So i decided to go barebones with it and tore it apart. It still wouldn't boot with only 1 2 gig stick of RAM and the CPU running. I then purposely half-assed reattaching the second stick to at least get a sign of life from the POST error messages. Nothing. no sounds. I slowly reattached everything, testing to see if it would boot. It wouldn't. I figured, maybe the RAM just sucks. So i swapped it out with a known working stick and got no change. I cleared the CMOS (with both the battery and the jumper(yes the bloody thing was unplugged when i did this)). I sent back the motherboard thinking it was flatlined. They sent it back saying it was perfectly fine. I checked everything in other systems (except the CPU) and they all worked fine. Then I noticed that the heatsink had no thermal compound on it, so i threw some on and still got nothing. You can tell I was getting desparate. I've tried every aspect of input and output items(ie keyboards, mice, monitors ect.) and got nothing. The only thing left to not be working is the CPU, but i have no way to test it. I cannot find another socket 775 computer to save my life!

Any ideas on what the heck is wrong with this Failienware? :)
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#2
123Runner

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If you can find out what is causing this...

So here's the situation: when ever I plug in the computer to the wall, the keyboard lights up along with a few spinning fans, but this is just it doing a test I believe.

, then you will most likely have your answer.

No computer that I have ever built or worked on will flash the keyboard lights as soon as you plug it in. As I recall there will be 5vdc on the board from the PSU. There will be no fans running.
When you push the start button the board receives a signal to turn on(after certain conditions are met). The fans turn on and you also get the num locks, scroll locks, and caps lock lights to flash. This is the basic startup.

What did you us e for barebones testing on the desk?
Are you getting any beeps?

Barebones components
Motherboard, processor, and cooling fan
Graphics card
One stick of RAM
One hard drive
One CD ROM drive

If you leave the CD rom out of the equation (1 component less needed for trouble shooting) then you should get the bios boot up screen. Since you have not installed an OS, you will get something to the effect "no OS found"

Bare bones trouble shooting

123runner
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#3
Diarmaid

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thank you for your response. In reply to your questions/suggestions, I'll answer them in order

The keyboard gives me no lights or anything when ever the system is running. Its just there to look pretty at that point. I can't explain why the keyboard flashes and all of the fans whirr once it's plugged in, but it's most likely the PSU because the old one didn't do this. (The fans are molex, so its not going through the motherboard)

The bare bones set up was exactly what you described, using different combinations of the disk drives.

Also, I have never recieved a BIOS screen. I can't even tell you want my motherboard's loading screen looks like.
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#4
rshaffer61

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Take the system apart and run a bench test outside of the case.
Attach the following only:

place the motherboard on a piece of card board larger than the motherboard,

this will eliminate a short from the mobo to the case which could be a possibility
Install the cpu with, 1 stick ram in dimm 1, power supply, case switch and case speaker
Connect ps2 mouse and keyboard along with the monitor
If the computer now boots into bios you most likely had a case short so make sure when installing the motherboard in the case that you use standoffs and they line up with the mounting holes in the motherboard and none of the standoffs touch anything else on the underside of the board.
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#5
Diarmaid

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I just attempted to start it up on the cardboard like you suggested, still nothing.
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#6
123Runner

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Lets go simpler yet. A PC needs only 3 things in it to boot. The CPU, the memory, and a video card. Attach a monitor so you can see POST.

Some steps to follow. From http://www.charliemaurice.com/?page_id=239

Lets say that your PC doesnt even get that far. You get your POST screen, but it never goes off of it, or nothing ever comes up on the screen. To troubleshoot this, we are gonna use the KISS (Keep it Simple Stupid) method. A PC needs only 3 things in it to boot. The CPU (for the love of god dont take the heatsink off of it), the memory, and a video card. Everything else is non-essential therefore we dont want it. So disconnect everything from the Motherboard side. Disconnect all IDE cables, all SATA cables, floppy cables, and remove all PCI cards. Also disconnect everything from the back side of the PC except the power cable and the monitor cable. Now, if it gets to the part where it says no OS (operating system) found, add things back one by one until it fails, you now have your bad component. Lets say you have only your cpu, memory and video card in and it still doesnt POST. Here are the next steps. Do the fans come on when you hit the power button? If not, the CPU is bad (could be mobo too) or the CPU isnt seated correctly. Reseat the CPU and try again. So the fans come on eh? Good. Now is the fun part. Remove the video card and try to turn on the pc. Does the computer beep at you? If so then the video card is probably bad. Replace it with a known good and try to boot. If not, remove the memory (now you only have the cpu in the machine). Now does it beep? If it does add the video card back and see if its still beeps. If it does still beep with only the cpu and the video card in the memory is probably bad (if you have more than 1 stick, put 1 stick in at a time and see if it boots…might be only one bad stick).


Still part of my concern is the fans being on when you 1st turn it on. The PSU doesn't fully turn on till you push the power button. Most fans in computers run from the 12vdc and thats not available till the PSU is on.

Steps for POST

Are you getting any beeps?
Is the speaker connected.?
Generally you will get a beep sequence indicating the failure.
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#7
Diarmaid

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I just tried it, but still nothing :) maybe the speaker is out, but I highly doubt that. I've tried connecting the speaker with two different polarities (not like it matters)just incase that I had plugged it in wrong, but I cant get a sound out of it. Could a burned out CPU cause all of this? I think it was refurbrished, but i can't find the receipt to be certain.
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