Long Story... Yes, it's long, but I'm trying to be thorough and cover everything I've tried.
Here is what I've got. Intel P4 3.0/Gigabyte socket 478 mobo 2x256 Kingston pc3500 hyper x

The begining:
Ok about six months ago I was playing an online video game, FFXI to be exact, when all of the sudden my computer froze. Mid sound effect and video capture just stopped. Done. So I powered it off the computer and let it sit for about 5 minutes while I went and had a smoke. I came back in and powered on my computer, POSTed fine and started the windows XP boot screen and then the computer shut off, so I turned it back on and this time, no POST. The computer gets power and the fans all come on and the hard drives spin up, but the monitor just says NO SIGNAL. So I'm thinking my VC is toast and I just happen to have my brother's computer at my house while he's in Iraq and he just happens to have the same VC as I do, (ATI Radeon 9800 pro 256). So I take my VC out and put it in his computer, boots up and turns on fine. I used his VC in my computer and still NO SIGNAL is displayed on all 3 of my monitors. Needing some things off my HDD I put my C:\ Drive into his computer and after a few tries it boots up and recognizes all the hardware except his on-board LAN. So, needing to get on the internet, I took my NIC out of my computer and put it in his, booted it up and get a NO SIGNAL error on the monitor... Ok, so this is weird, I put my C:\ Drive back into my computer but not the NIC. At this point the computer is a little over 2 years old and during that entire 2 years I couldn't get my onboard LAN to work on my Gigabyte mobo, which is why I had to get a NIC. Anyway, so I boot up, it POSTs and I log into windows and my onboard LAN starts working. Whatever, I'm stoked because I thought it was just my NIC that caused the problem, but after about 20 minutes of browsing, my computer shuts itself off, not log off, and shut down, but just off. Turn the bugger back on and it doesn't POST and the monitor says NO SIGNAL. I give up and go to my brother's computer and continue to use it for the next 4 months.

His Computer Dies Somehow I killed his computer while trying to add another HDD to it, but that's neither here nor there. It's time to revive mine. I get my computer out of the basement and take the whole thing apart... everything, HDD's, Proc, PSU, and even the mobo out of the case. Dust the **** out of it and reassemble it. Get it all plugged in and power it on.... POST!!!!! Horray, (thinking dust might have been the issue) and I log into windows. Not wanting to dig up and ethernet cord, I decide to power off and install my wireless NIC, turn it back on and no POST.. booo. Incidently, it was the same pci slot that my NIC was in all those months ago. So, I power it off, and take the wireless card out and still no post. Tired of dealing with it, I turn on my XBOX and do that and FFXII for the next 2 months.

Round 3 So just the other night, the time comes that I can't get by with my friends borrowed computer and my work computer and I need to get mine going. So, I take everything apart. (again) and redust it, even though there was none and during reassembly, I put a nice big stretch of duct tape over that PCI slot so I won't be tempted to use it again, say a quick prayer and power it on. POST! Oh man this feels good, and I Log into windows. Then I shut it off, and let is sit for 2 minutes, and turned it back on POST! Allright! I log back in and do 6 months of windows updates and leave it sit on overnight. I power it off and go to work. My wife turns it on, and plugs some speakers into the onboard sound and lets my kids watch a movie on it, and then shuts it off. I come home and try to turn it on, and no POST. Also, every time it doesn't POST, I get the same NO SIGNAL error staring at me.. watching me..

Round 4 Valentine's Day. I take everything apart again, blow off the non-existant dust and try again. POST! But a weird error after the Memory and HDD test, saying something about windows not booting properly or something and to hit f1 to continue or DEL to enter setup. Now back on round 3 I got this same error, and F1'd and off I went, so I F1'd this time and the monitor went black and it stopped doing anything, I let it sit there for 10 minutes just in case, and then power it off, take everything out again and put it all back together and this time no POST. I've got to tell you these ups and downs are really trying. Well I went looking for a socket 478 mobo and they're pretty hard to find but this is what I'm thinking of buying.

Newegg.com - ASUS P4V800D-X ATX Intel Motherboard - Retail

The issue I have with that is spending $86 on something that might not fix the issue. Also I got the OK to spend upwards of $1000 at the end of the summer from my wife on new computer parts if I can save it up out of earning extra money that won't take away from bills and other ****. Currently I have $150 saved up, so this 86 would be coming out of that. Any opinions, advice or flames anyone wants to offer up I'd appreciate it.

Thanks
Zak


Edit: I forgot to mention that when my brother's computer died, part of the troubleshooting I tried then was to replace the PSU, which is also now in my computer.

Hey Zak,

Sorry I didn't welcome you to PCHF earlier.

Reading what you have talked about, problems when adding another NIK to your brothers PC, plugging in speakers, playing games and watching video before it's switches off, all require more power. Do these power supplies have enough juice? Check out this web site, which is useful for calculating your PSU Requirements (add 15% for capacitor aging if your PSU is a couple years old): eXtreme Power Supply Calculator - What Power Supply Do I Need

With regards your $1000 allowance from your wife , I think with this you could easily just buy another PC from Dell (is the most popular and cheapest ATM).