Thanks for the responses. Here is the response from asus tech support. Not bad for a first reply.
For those that were confused by my post, sorry I was up all night. I was trying to improve my home pc by swapping a better (just a little) mobo I had in my cad/cam pc at work. Then one of them still isn't working. I think it's the mobo, because I swapped in everything else. All the parts I tried have worked on other pc's after trying them.
Dear Friend :
Thank you for contacting ASUS Customer Service.
My name is ZYC, and I would be assisting you today.
Please take your motherboard and others parts out off the case ,
put motherboard onto a flat desktop,connect everything need to boot with,
then try to power on system,
will the system powered on and boot up ?
if not ,
Please reset CMOS defualt by clear CMOS by:
1. Cut the power supply for whole system and open your case;
2. Take out the Cmos battery from the battery socket;
3. Install your battery with "reverse side" that means turn the battery 180 degree and put in into battery socket;
4. Hold about 30 seconds, then take out the battery and install it normally;
5. Plug the power cord and Power on .
if still bad , please take all your ram sticks out from motherboard , and power on . will it give you long-long-long repeat beep warning ? if so , please clean your ram co! nnectors with alcohol or with a clean rubber then install your ram sticks back, you can first install 1 stick of ram , if the system can boot with 1 ram stick , add another.
After above steps if the system does not boot and give no beeps, please take out your AGP vga card , power on , will it give you 1 long and 2 or 3 short beeps followed ? if so , please try to clean your VGA card connector and install it back to motherboard , or you can try to use another VGA card test again.
if nothing changes ,i suggest you take your motherboard and other parts all out off case ,then put them onto a flat desktop,connect everything needed for booting ,power on it .
if the above steps are all not helpful , i think maybe your motherboard or your CPU is faulty , you need take a future test for each one and make sure on earth which part cause system won't boot.
If it is due to motherboard faulty ,
i think you'd better contact board reseller or local asus se! rvice center or motherboard dealer for help to get a RMA.
if it is impossible to contact your dealer , please contact :
ASUS COMPUTER INTERNATIONAL
Or you can check this link for contact information :http://usa.asus.com/contact/contactindex.htm
Thank you for using ASUS products and services!
If you have any problem about our products, you can visit our support site below to search the solution at the first time!http://www.asus.com.tw/support/support.aspx
ASUS Customer Service Center (Beijing, China)
The suggestion above about the battery upside down doesn't change polarity because of the way the case of the battery is designed. All it will do is short the cmos out like the jumper does. I think.LOL
The bad board is an early A7N8X-Deluxe rev 1.04 It was a replacement for a DOA new board. I had used this one for about a year. The proc is an XP2500 barton. It IS possible that I tweeked the board installing the HSF. I'll post the final diagnosis. LOL But I already ordered a Biostar M7NCD $47, better specs less 1 lan. DAN
MSI K8N-Neo2 Platinum, AMD 64-bit 3500+newcastle, ASUS FX-5950, 72Gb WD 36GB Raptor x2 raid 0, Ballistix 1Gb (dual 512 pc3200), Allied 500W alum PS