Computer not starting up.....please help!

[rexxe]

Hello,

I have just built a computer which uses EPS 12V power connectors on the motherboard. I have everything hooked up right, I have checked about 10 times now and have tried disconnecting everything except the motherboard connection to the power. When I turn on the PSU, the CPU fans spin for a split second and the same goes with the PSU fan. After that, absolutely nothing happens. I have tried everything, changing the power switch to the reset button, removing everything else, but nothing is working. How do I know if it's the PSU or the motherboard or something else? I'm pretty confident it's not the switch to turn on the computer becuase I cannot imagine both the reset button and the power button not working.

The PSU is a AMS Electronics Mercury 550W and the mobo is Tyan K8S Pro.

HELP!

Thanks,

Rexxe

 

[Ozz1113]

Unplug everything. Take a paper clip and jump pins 4 and 6 on the motherboard connector from the PS. Plug the power into the PS and turn it on. You should see the fans spin....If it doesn't, the PS may be bad. Even hook up a large cooling fan and see if that works...
Hope my diagram below helps.

--
DDD4D6DDDD
DDDDDDDDDD

 

[rexxe]

Hmmm...you show only 8 pins across but my power connector has 12 pins (it's not an ATX it's an EPS 12V connector). Do you know what color the wires to jump are? Is it gray jumped with black?

Thanks!

 

[L1FE]

if you can, find a known good psu and try that on the mobo.

 

[mechBgon]

That sounds like it could be a symptom of a short-circuit. For example, if there's an extra standoff under the board that does not correspond to a screw hole in the board, then that standoff might be causing a short from underneath. Or if the springy EMI contacts on the rear I/O shield get into the USB or network jacks, same thing.

Also, I've never heard of that power-supply manufacturer and that makes me suspicious (doesn't take much!)

If you're not getting anywhere, then a full list of specs including the exact model/part # and quantity of everything would be helpful. For example, "four 512MB Corsair CM72SD512RLP-3200 Registered ECC modules in DIMM slots so-and-so", not just "2GB of Corsair PC3200." And so forth.

 

[rexxe]

Also, forgot to mention that the power light on the front of the case is lit. I don't know if that means anything at all. I will look into the short cirtcuit. In my description of the problem, I should clarify what the fans do. They literally jump/move for a split second, not really spin as I described.

 

[rexxe]

I took the motherboard out of the case completely and placed it on an anti-static bag and then plugged it in. Still nothing heppened. The only thing I guess the motherboard is getting is the standby power which must be why the fans jolt for a split second. Other than that, I'm at a loss. If it was the motherboard, wouldn't there be a burn mark or a burning smell if I shorted it out? I'm going to purchase a power supply tester tomorrow which should hopefully let me know if this PSU is good or not.

Here are the specs of the computer:

Tyan K8S Pro
2- 1 gig registered ECC DDR400 RAM sticks. Brand is PQI and it's their Turbo series
AMS PP-5503 Power supply (http://www.amselectronics.com/)
2 - AMD Opteron 244 processors

That's about it....

Thanks,

Rexxe

 

[mechBgon]

For a full-on dual-Opteron rig, you really ought to have four (or else eight) matched modules, or you're only firing on two of the four total memory controllers. Sorry if that's unwelcome news Anyway, what exact memory slots are the two modules in?

 

[mechBgon]

I have the Thunder K8S Pro's manual downloading, but it's 10MB and I've got a 56k connection so in the meantime I scavenged my collection and pulled out the Thunder K8W manual. If the two are as closely related as I think, then for two DIMMs you would put your memory in these slots. That isn't the only feasible option but the others would involve giving both modules to just one CPU. Anyway, I'll drop by tomorrow and see how things are going.

Bigger picture: what did all that stuff cost? I wouldn't gamble on the PSU if there's the slightest doubt about it, go and get an Antec True550 EPS or a PC Power & Cooling unit or something else of known high quality. You know you'd be kicking yourself if your PSU went and nuked your loot

 

[rexxe]

I have both memory sticks in CPU1's slots 1 and 2. According to the manual putting memory in CPU2's slots is not necessary for dual CPUs, also putting them in the slots you recommend yields only 64-bit support instead of 128.

If I determine that the problem is definitely the PSU, I'll look into other PSUs. I've got a sinking feeling it's the motherboard, but we'll see what happens when I get a tester.

Thanks for your help!

 

[rexxe]

I bought a power supply tester and it's definitely the power supply. Only 1 light on the tester lights up. I just hope there was no damage to the motherboard. But, for now, looks like I'm going to be RMAing the power supply.

Thanks for your help

Rexxe

 

[rexxe]

I just received a new PSU and now there's a new issue. If I put the motherboard on a cardboard box, it starts up. When I put the motherboard in the case with no screws, it starts up. However, the second I put a screw in the motherboard, it will not startup. IN fact, what happens is that it starts up for a second and then the power cuts out, most likely because the PSU has short circuit protection. I have tried reseating this thing 100 times and have looked for any metal pieces below the motherboard. Also, I have the exact number of standoffs that are required by the board. I'm at a loss on how to fix this problem. It seems to me that there is a problem with the mobo if it keeps short-circuiting anytime I put a screw in it.

Thoughts? Any advice or help you can give me?

Thanks