HELP: New PC won't turn on + loud POP

[devi0us]

Hi guys, I've built 2 PCs before so I'm not exactly a greenhorn, but what happened last night has me stumped and troubled.

Firstly, a list of components:

MOBO: MSI K9AG Neo2-Digital AM2 AMD 690G HDMI ATX AMD

CPU: AMD Athlon 64 X2 4400+ Brisbane 2.3GHz 2 x 512KB L2 Cache Socket AM2 65W

PSU: OCZ StealthXStream OCZ600SXS ATX12V / EPS12V 600W

RAM: G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)

HDD: Western Digital Caviar SE16 WD3200AAKS 320GB 7200 RPM 16MB Cache SATA 3.0Gb/s

Case: COOLER MASTER Centurion 534 RC-534-KKN2-GP

No GFX card because mobo has onboard (the PC is for my girlfriend).


I put the whole thing together last night with my girlfriends brother and when we tried to turn it on, nothing happened. "Okay" I think and go to press the button again. We hear the machine briefly turn on, fans whirring and all, and then turn off. I press the button again and this time, nothing happened except a loud POP like a cap gun, or electrical discharge from a Tesla coil. Then we smelled the horrid stench of burnt electronics.

We thought it was the PSU, so we quickly tested the new PC with an old PSU lying around. After the POP, with either PSU, after we tried to power on the PC, it most of the time NOT start up, but the Power LED in the front would blink. Sometimes the PC would powerup for a second then turn off.

We started dismantling the PC, piece by piece, testing each part to see what worked and didn't. We found that the RAM worked in another PC, and the new PSU powered up an old Pentium 4 PC that had no ram or HD in it (that PC gave two beeps on bootup though, must be the lack of ram or HD?). We couldn't test the CPU because her brothers Dell had a HSF that seemed to be soldered onto the mobo. We also couldn't test the HD or mobo.

I also tried to see if I did any wiring wrong, but I couldn't find anything out of place. Even if I did the power, reset, etc wires wrong, could it have done this much damage? Where'd the blow out happen and why? We were careful the whole time to look out for electro static discharge, so it couldn't have been that...

Right now we're looking at RMAing at LEAST the mobo. Any help/tips/pointers you guys could provide would be greatly appreciated.

 

[mechBgon]

First be certain that you didn't mix up the 4-pin ATX12V cables with the 4-pin section of the 20+4 main power cable. That would be a nasty error, since the voltages are not the same. ATX12V cables contain only yellow (12V) and black (ground) wires, and should go in the separate receptacle for that type of cable, never into the 24-pin main power socket.

If that wasn't the problem, next remove the motherboard from the case and examine it for possible sources of the noise you heard. Also look at the case for any smoke/burn marks that might reveal a short-circuit situation. If nothing is found, try powering up the motherboard and essential components while the motherboard is laying on cardboard outside the case.

 

[robisbell]

visually check all the motherboard capacitors. I'd also manually check the voltage on the PSU.
as for the dell, if you want I can help you in getting the hsf off of the processor in it, so you can remove that processor and test yours.

 

[devi0us]

mechBgon: I didn't mix that part up thankfully, but I will check the mobo ASAP.

rosibell: I check the capacitors, and would love to know how to remove the HSF on that Dell, its a Dimension 5150 I think. I would get back to you on the exact model.

Thanks a lot for the quick responses guys.

 

[Billb2]

Originally posted by: devi0us

CPU: AMD Athlon 64 X2 4400+ Brisbane 2.3GHz 2 x 512KB L2 Cache Socket AM2 65W

We couldn't test the CPU because her brothers Dell had a HSF that seemed to be soldered onto the mobo. .

Then later...........its a "Dimension 5150"

Am is missing something here? You want to plug a AMD Athlom into a Intel P4 socket?

 

[devi0us]

I definitely have the model name/number wrong then because her brother is running an Athlon X2 4000+ for sure.

robisbell: I don't have the tools to check the voltages manually, and I understand that software isn't accurate right?

What are the chances of the CPU having been damaged? Would I be able to see any damage? I checked the cpu and it looked fine to me.

 

[robisbell]

you can't visually check a CPU for damage. software is good idea if the power supply is fauly, but not always reliable. you only need a multimeter to check the voltages. did any of the motherboard capacitors look swollen on the top or sides?

if the system is using a stock Heatsink. then let the system warm up and the paste should loosen up so you can remove it, you may have to remove a clip or 2. the model number would help immensely.

 

[devi0us]

Guys, I think I've gotten to the bottom of this...

I did NOT use the brass risers or standoffs. In other words, I screwed the mobo directly into the case, the probable cause of my problems... Man I messed up bigtime.

I'm still going to get you the model # robisbell, so don't give up on me. =/

 

[robisbell]

how did you get the face plate to fit if you did that? you've at least shorted out the board, at minimum.

let me know via PM on the other issue.

 

[Modelworks]

Originally posted by: devi0us
Guys, I think I've gotten to the bottom of this...

I did NOT use the brass risers or standoffs. In other words, I screwed the mobo directly into the case, the probable cause of my problems... Man I messed up bigtime.

I'm still going to get you the model # robisbell, so don't give up on me. =/

If you didn't use standoffs, your motherboard is toast.
You probably killed any number of parts.

 

[mrblotto]

Originally posted by: devi0us
Guys, I think I've gotten to the bottom of this...

I did NOT use the brass risers or standoffs. In other words, I screwed the mobo directly into the case, the probable cause of my problems... Man I messed up bigtime.

I'm still going to get you the model # robisbell, so don't give up on me. =/

D'oh!

 

[devi0us]

Yeah, I made a novice and fatal mistake, so much for not being a greenhorn.

Thanks for all your help guys, I'm gonna check every component again to see if it works and remember to use the risers next time!

 

[robisbell]

be glad that it did not catch anything on fire, seen many first time builders have to call 911 because it caught the house on fire.