Do you see any activity on the screen at boot up? Also, you can place original fan, just to try, you need to make sure that MOBO is working.

Did you try reinstalling the original CPU? And a new power supply?

If you're tired of dickering with the stock mainboards, you can move up to an aftermarket microATX like this and a low-end CPU (that will outperform the high-end CPUs of the 3000's day).

Ok Here we are 2 weeks later. This is my status on this machine. I'm close to giving up which would be a shame. I installed a new HD and 2 gigs of (1gig ea.)matched RAM. I reinstalled the OS (windows xp home) After  I got some driver issues resolved, it booted up and had Internet connectivity and was performing well. Where my problems began to get ugly: I installed a new 3.4ghz pentium(original was 2.8) incorrectly and bent 4 of the pins. So I had one extra and after paying closer attention, got it installed properly. I moved  a tri-cool fan to sit directly on top of the heatsink and spliced the connector from the old fan to the new one as the connector did not match the MB. Splice was color for color. Upon start-up (after triple checking all connections) I got an amber power light, a continuously running processor light, no lights at all on the back of the machine(which never worked on the original machine straight from Dell) Fan works great and heat-sink is cool to the touch. My first assumption was that I damaged the MB when I installed the first processor incorrectly. So I bought a refurb MB from a seller in RR, Tx. Installed with no issues and an undamaged processor by the book. The result was the same. Amber power light and continuous processor light and no screen display. The only thing I didn't change was the fan. I left the new fan connected to the board with the spliced connector from the old fan.

Should I trash it and chalk it up to a bad experience or is there something simple I'm just not seeing? The bios revison was done prior to installing the processor so that's not an issue. Prior to installing the first new processor  and fan everything was good. So by process of elimination, I've narrowed it down to the fan connector and what the MB is responding to as far as the new fan is concerned. Does anyone see something questionable about what I've done? I'm trying to learn so please be patient. 

Hi there  rdunnill !  Yes I did try the original CPU to no avail. The PS seems to be working fine. Could there be an issue with the fan connector to the MoBo? One of those wires is a speed sensor. Is it possible that the Mobo isn't letting the machine boot due to that connector and the new fan wired to it? Would the mobo you suggest fit my machine?

It will fit, but you should remove a ninth, non-standard lead from the front panel USB connector. The front audio port will not be connected unless you rewire the Soundblaster-type connector for standard Intel HD.

You'll need a 92mm case fan, but if you already have a 92mm Antec Tricool, that will work very nicely: I have ascertained that the Antec properly mates to the factory mounting grille at the back of the chassis.

If you don't have a SATA drive, you'll need an IDE host adapter card like this, or you can use a standard SATA or SSD drive.

It's an ASRock H77M LGA 1155 Intel H77 micro-ATX. Yes, onboard video is included.

I'd suggest an Intel Pentium Dual Core G630 for a CPU. You'll also need memory, and 4gb of Crucial Ballistix is a pragmatic choice.

The motherboard will bolt in, although you'll have to remove the thread-in OEM heatsink mounting bosses, which are spaced for Socket 478.

If your power supply is in good working order, it should be sufficient. The new motherboard and CPU likely consume less power than the originals. Of course, the new combination will handily outperform the original Socket 478, and will have other benefits, like video decoding in hardware.

So what is the model # for this Micro ATX mobo? Is a graphics card included with this board? Is my PS adequate or do I need to go to 400 watts or more? Also what about the processor? Any links you can provide are very helpful. Are the attachment points in the 3000 ok for this board or do I need to plan on making changes to make it secure inside the case? Thank you for your help :-)

The Dell 3000 case is homely but otherwise very practical, being spacious, has multiple drive bays, and solid cooling. It is sturdily constructed of sheetmetal of significantly heavier gauge than many aftermarket cases. Unlike some later models like the XPS 7100, it will take power supplies of non-standard length, so if you want to swap in an OCZ Fatality or other gaming unit, there will be no problems.

I updated the links and if you do go this route, let us know how it works out. You're looking at $150 to replace the motherboard, CPU, and memory, but you'll get premium features over a low-end product like USB 3.0 and SATA 6gbps.

Hi there again. I think this is the route I'll go. The link for the processor was a bad link. Could you resend?

Tired of screwing with Dell stuff and pretty much no upgrades offered to repeat customers much less a 1st time customer. You'd think Dell could be more customer friendly but I guess not. They'd still sell things even if it weren't a whole new system. There are all sorts of niche buyers who go elsewhere when they should be able to find it here. Ok I'm done ranting :-)

Wait a minute ... have you checked your front USB sockets for bent pins? It's possible that one or more pins is bent and shorting out the power supply.

If you do install the AS Rock motherboard, do so without connecting the front USB ports.