Self-built Computer Refuses to Power Up

[tagelmo]

I decided to build a computer and bought all of the parts about a month ago. Since then, no matter what I do, I cannot get it to power up. The exact same thing happens every time I try to start it up: when I turn on the power supply, a light on the motherboard turns on (it's located next to the 24-pin power connector), indicating that the mobo is receiving power. When I press the power switch on the case, the lights on the fans flicker for just a moment, and the fans twitch, but nothing happens. The light next to the 24-pin connector stays on, but the system gets no juice whatsoever; the monitor's power light stays yellow and it never wakes up, none of the hardware wakes up, and no beep codes sound. I originally built the system with the following:

Case- Aspire X-Navigator  
Mobo- Intel D945PSN LGA 775 socket  
CPU- Intel Pentium D 930 Presler 3.0GHz  
RAM- 1Gb Patriot 240-pin DDR2 667  
HDD- 320Gb Seagate Barricuda SATA 3Gb/s  
Optical- Sony DVD Burner  
Graphics- ATI Radeon x1600 PRO 512mb PCI-Express  
PSU- Turbolink 500W ATX-CW500P4 (came with case)

When I tried to turn it on for the first time, the situation described above occurred. I had heard a lot of stories that PSUs that come with cases are generally bad, so I bought an Antec SP-500 500W PSU. Installed it, fired up the system, and got the same results. At that point I took the mobo, CPU, RAM, and video card and fired them up outside of the case. Still the same result. There are no extra standoffs on the case that could be shorting out the mobo. Then I thought that maybe the mobo had been damaged by having the original bad power supply attached to it. I bought another mobo of the exact same make and model, installed it, still the same results. I put everything back into to case, and bought a new CPU. This time I got a Penium 4 541 3.2GHz processor that is compatible with my system. I installed it today- still the same results. I'm out of ideas. Can anyone please help?

After all of that, this is what I currently have installed:

Case- Aspire X-Navigator  
Mobo- Intel D945PSN LGA 775 socket  
CPU- Penium 4 541 3.2GHz*
RAM- 1Gb Patriot 240-pin DDR2 667  
HDD- 320Gb Seagate Barricuda SATA 3Gb/s  
Optical- Sony DVD Burner  
Graphics- ATI Radeon x1600 PRO 512mb PCI-Express  
PSU- Antec SP-500 500W PSU

*If I ever get this thing working, I would like to reinstall the original Pentium D processor

[GX1_Man]

Is this the same computer?

http://www.computerhope.com/cgi-bin/yabb/YaBB.cgi?num=1152840117/2#2

[tagelmo]

Yep, it's the same one. I haven't made any progress with it whatsoever.

[homer]

is EVERYTHING plugged in correctly?? CAREFULLY review your users manual for your mobo. TRIPLE CHECK that EVERY wire, compponent, and switch is plugged in correctly. also, insure that every component is compatible with your mobo.

i cannot stress enough to TRIPLE CHECK that EVERYTHING is in the correct spot.

[tagelmo]

OK, at about the fourth time I was checking all of my wires, I noticed a two-pin jack on the mobo. I looked at what it is in the user manual, and it says that it's some kind of intruder switch. It looks that if there were some kind of wire or plug on the door to my case, I would plug that into the intruder jack so that, as it appears, if it gets unplugged, the system would shut off and (I think) power wouldn't be able to be run through it. However, there's no such wire on my case door, and I have no jumpers to plug it with, or if it requires a cable, I don't know what kind of a cable it requires. This may be the culprit behind all of my woes, and if it turns out that these two little pins that I overlooked are the problem, I will feel like a total *censored*. Thanks to everyone who offered advice for my troubles for their time and their knowledge. If anyone knows what I can/should plug into those two pins, I think that it should solve my problem, and I will be greatly thankful.

This is from the mobo manual:

Chassis Intrusion
The board supports a chassis security feature that detects if the chassis cover has been removed.
The security feature uses a mechanical switch on the chassis that can be connected to the chassis
intrusion header on the desktop board. See Figure 20 on page 39 for the location of the chassis
intrusion header.

[tagelmo]

OK, I've been going over my wires, and there are two things that I'm not sure about.
First:
For my SATA hard drive, I have the data cable plugged into SATA port 1 on the mobo, and my options are SATA 1,2,3, or 0

Second:
I have 1 stick of RAM, which is currently inserted into Slot A DIMM 1, and my options are Slot A DIMM 1, Slot A DIMM 0, Slot B DIMM 1, Slot B DIMM 0.

Also, because I had always just been looking in through the side window, I had never noticed that when I hit the power switch on the case, not only is the little light next to the 24-pin connector on the mobo lit up green, but a light on the front of the tower is lit green as well. The power switch seems to function relatively normally, in that when I press it, these two lights turn on, and when I hold it in for several seconds, the green light on the front of the cabinet turns off, while the green light on the mobo stays on. It appears that something is recognizing that the machine has been "turned on" even though nothing works.

I've gone over the wires several times, and everything seems to be in place. My graphics card, RAM, and heatsink are all securely inserted/attached. Other than the possibility of the RAM or SATA cable being in the wrong place, I don't know what else to look for.

[tagelmo]

OK, so re-installed the Pentium D processor I have, and when I did that, I tried to be sure that it was well seated and didn't move when I locked the latch down or put the heatsink/fan on. I fired up the PC with just the mobo, CPU, RAM, and video card inside of the case. The CPU fan seemed to spin for a little longer this time, but it still stopped after a second or two. Still no beeps or anything. I am absolutely sure that everything is wired/plugged in/installed correctly. One thing that bothers me is that while (when all components are plugged in) the CPU fan spins for a second and the case fans at least blink and twitch, none of the fans in the PSU budge whatsoever. I haven't tested the voltages on the connections for this PSU yet, but because the light next to the 24-pin power connector lights up (and stays lit consistently) as well as the power light on the front of the case, it seems like at least some power is getting to the unit. I had bought the power supply new, and it's 500W, which should be more than enough for my setup. How can I be sure that the CPU is properly seated? Should my observation about the PSU fans concern me? Any ideas whatsoever as to why my setup absolutely refuses to start running???

[ale52]

Sounds like a bad motherboard.  Can you take the motherboard out of the case, place it on cardboard or something non-conductive, and try firing it up that way?

You might have grounded the motherboard when installing it in the case.  By "benching" it you will remove that possibility.

It if still doesn't work, try another power supply.

If THAT doesn't work, replace the motherboard.

Alan <><  

[tagelmo]

Yeah, I've tried firing it up outside of the case already, and I still got the same results. One thing that has me a little worried is that while the fans and everything show movement/activity if even for an instant, the internal fans of the power supply itself don't even do as much as twitch. I've sent an e-mail to the tech support at Antec's website, and last time I did that they responded pretty quickly. Pending that response, right now I think I'm going to buy an ASUS mobo, since those seem to be the most trustworthy mobos out there.