ECS K7S5A won't boot after new HSF

[TheJTrain]

Background:
I'm fairly competent with building systems, replacing components, etc. - I built my system and have successfully replaced the CPU, the HSF later, the video card, case fans, etc. But I'm a little stumped at what's causing my current problem.

Problem:
I put in some new components to try and make my machine quieter, and once it was all back together, it doesn't even try to boot - the LED flickers once and nothing happens, no fans spin up, no mobo beeps, nothing. The components I replaced were the HSF (mounted a SLK-900U using the x-plate on the back of the mobo through the mounting holes around the CPU), added a Zalman Fanmate to the Panaflo fan on top of the SLK, and floppy/IDE cables (went to round cables). To accomplish this I had to remove the mobo from the case and re-mount it. I've also had intermittent trouble with the CMOS, where once every few months it refuses to boot, and when I open the case, move the Clear CMOS jumper to Clear for a few seconds, then back to Normal it boots fine. I bought a new battery and waited for it to happen again before I opened the case to replace it. It happened the other day, so I opened the case, cleared the CMOS and replaced the battery, then decided to put the new HSF and cables in before I turned it back on. Maybe the new battery's a bad one? Would a dead CMOS battery prevent startup or just prevent the BIOS settings to be retained?

What I've done so far:
I had a little time to monkey with it - I disconnected the Panaflo fan (which does have an RPM sensing wire) on the SLK from the mobo and reconnected the old fan I replaced, still no activity, so it's not the mobo refusing to start because it can't see the CPU fan spinning. Mounting the HS with bolts through the mounting holes was a new thing for me, but if it was improperly mounted the system should still at least start up, even if the CPU will fry in 10 seconds, right? The PSU is good, I hooked up a tester to the 20-pin mobo connector and it comes on and powers the case fan and drives. So I'm thinking something must be shorting the mobo somewhere. Does this sound like it might be the problem? Even though it's a pain I'll probably have to just pull it back out and see if it starts up from outside the case, then I'll try to remount it. I'm wondering if the x-plate on the back is messing me up somehow. Anyone have any trouble with HSF that use the mounting holes and a plate on the back of the K7S5A?

Jason

 

[brentkiosk]

Jason,

I don't know if this is of much help. I did a Mobo transplant yesterday and the system did not boot at first. All fans spun, front panel lights lit, etc, and the PSU seemed OK with the old Mobo. After several hours of screwing around, I touched the cables to extra USB ports and the were downright hot! I had plugged them into the wrong connector on the board generating a short somewhere. So, I would suggest you keep looking for shorts. Both my K7S5 boards are mounted with screws through the holes, but the clearance is a little scary.

Hope this helps.

Bob

 

[Slogun]

My old Alpha HSF was bolted through the holes of my K7S5A, but I never had any plate on the back.

The symptoms you describe could also be caused by something as simple as a poorly seated or malfunctioing AGP video card. Before you pull the whole mobo out you might first try swapping in a different vid card if possible.