pc won't boot, no POST beep

[noobb]

Hi, guys!
Getting crazy here and need help. I decided to put together a low end pc for media playback. I bought a "pulled out but tested working" Duron 1,6 and open box chaintech 7NJL6 mobo on clearance in my local pc store. Did not boot. No POST, no beeps, no video. I had old k7s5a socket A mobo laying around so I checked it too. same story. I decided that I got a dead Duron. Went and bought a new Duron 1.6. Same story. Pulled mobo out to avoid short circuits, tried another power supply, case, unplugged everything except mobo, agp card, and processor. Same story - CPU fan is turning, ide devices and system fan power up if connected, still no POST, no beeps, no video on monitor. Cleared CMOS, even pulled battery out.
Finally went ahead and read mobo instructions. They both support Duron up to 1.3 only. Does it explain no POST? Well, 7NJL6 mobo has a sticker that it supports Duron up to 1.8.
Don't have another socket A processor so can't update bios on mobos.
Completely lost about what to think. System speaker does work - checked with my old intel mobo. One power supply is Coolmax and supposed to be protected from short circuits etc. Suppose I got chaintech lemon, will it explain why k7s5a doesn't POST if it only supports up to 1.3 Duron? Could it be agp video card (not integrated) since with agp failure I am supposed to hear beeps? Is there single hardware failure that can be responsible for all of this? Any thoughts will be appreciated

 

[nebula]

Try clearing the CMOS on both boards, hopefully that will get it going and then you can flash the BIOS.

 

[noobb]

Originally posted by: nebula
Try clearing the CMOS on both boards, hopefully that will get it going and then you can flash the BIOS.

Thanks, I did on both with jumper and unplugged psu and still no go. Even pulled out the battery. Is it correct that if my k7s5a don't support duron over 1.3, it won't even pass post?

 

[corkyg]

Try different memory. No memory will result in no POST or beep. Also, an improperly seated CPU will cause that as well.

 

[noobb]

have 2 memory sticks, tried them separately. CPU seated properly, arrow aligned with lever (lift lever, insert CPU, put lever down - I've done this before) and the way pins are on socket A CPU you can't insert it other way. I use thermal paste on CPU and not sure if I do it correctly, but that can't kill CPU that fast, right? Can it be short circuit somewhere or video card?