computer is a COMPAQ presario 5000us but not so much anymore...

over the course of its 10 year life, its received:
1) a new hard drive - 160gb instead of 40gb (seagate BRAND HDD)
2) new RAM - increase from 128 to 512 (both 256 Samsung)
3) new CPU - increase from 1.2ghz to 1.4 (don't know celeron or P3)
4) graphics card (ATI x1050)
5) new power supply - for sata power to backup hard drive (500w superstealth [can't remember brand])
6) said backup hard drive - 1TB sata drive (Seagate)
7) RAID card for sata connection (via tech)
finally, new mobo - previous one was causing restarts and thus was replaced. (gigabyte don't know model)

in the long run, I could've just built a new computer with all I spent on those parts, then again I got the parts for cheap ($5-10 for each, except HDD)

on to the issue.  its worked fine for the past year or so, but now its not wanting to boot up all the time, its starting less often than its not and now its frustrating.  the fans spool up, the hard drives spin, the CD-Rom opens and closes, but the mouse and keyboard don't have power at all, no beeps from computer.

where do I start at diagnosing?  I went to Fry's to buy a POST card but they don't carry them, so I'll have to buy one online meaning I'll have to wait for that...but maybe some folks here can help

edit:  added brands to 'upgrades'Don't spend money on a POST card when most diagnostics can be done FREE...

HDD) Dload and run the Free diagnostics from the HDD manuf. site...follow the INFO on creating a bootable CD.

Memory) Dload and run MemTest...again follow the info above...

Vid card) If applies: Borrow a known good card and swap it in there overnite and see...

Power Supply) Borrow a known working one of the same or greater wattage and swap it in there to see if that's the culprit.

Heat Kills) DLoad install and run SpeedFan and check your Temps against the manuf. tolerances for those components.

All of the above tests will cost nothing but time...but they will get you closer to a solution of what is the issue with your machine.as for your suggestions:

ran HDD test from UBCD4Win, no bad sectors of either HDD. (ran it about a month ago...randomly)
ran memtest for 200% - 0 errors (ran it less than a month ago - I check this monthly)
didn't NEED a video card, on-board graphics didn't work either...
PSU is fairly new, but swapped with the old one, same issue - no start
I'll definitely install speedfan when I get the system up and running again.  I'm interested in the temps it was running at.


well, I pulled each accessory 1 by 1, video card last so I was left with a bareback system of mobo, CPU, RAM, PSU, HDD...

pulled the RAM to see if I'd get a beep...did the same it's been doing.  pulled mobo and reseated, did the same thing.  I found the old motherboard which never had trouble starting up (just crashing) and the whole system, including all peripherals, and it started up just fine.  of course as soon as I clicked an icon in windows it restarted on me and drove me up the wall....but at least I know it was the motherboard that has gone bad

so now I have a dilemma, pay $15 for a replacement 370 SOCKET mobo, or upgrade motherboard to 775, RAM to 2-4GB DDR2, CPU P4 or core2duo for $50-75...

although, I think I'm going to take my advice from before and just go ahead and build a new computer...

thanks for the help.Good flowchart diagnostics on your end...

As to what to invest in only you can really decide that but i'd lean towards a new build with current prices.

If you don't need a new monitor or case you can build a screamer for about 6-700.00 Bucks right now...