Mobo Troubleshooting Info Request

[jlharvison]

I successfully overcame the foolproof design of the main 24-pin power connector on my motherboard with the 20+4-pin connector from my power supply. It's just takes a big enough fool...

Anyway, I accidentally plugged pin 11 into 12 and pin 23 into 24 (two legs of the +4 power supply connectors hanging off the end of the mobo socket). Upon my switching the power on, the cooling fans and power LED came on, but the machine did not post. I knew I had screwed something up, so I turned the power off, checked it out thoroughly, and discovered what I had done. I corrected the problem, but the machine exhibits the same behavior. I figure I fried the mobo.

I do not have another desktop computer, and my friends have all upgraded from the s939 platform, so I can not check my RAM (DDR400) and CPU(x2 4800) to see if I killed them too.

Does anyone have enough knowledge of the mobo circuitry to know if RAM or CPU damage is likely with the mis-connection I described above? It was an MSI K8NGM2-FID, if that matters.

I'm using this as an excuse to upgrade, but I'm also thinking of getting a cheap s939 mobo and turning this box into a HTPC.


(btw, I realize that this was an extremely dumb thing to do)

 

[MTDEW]

If the mobo still starts, and fans spin and power light on.

I'd pull everything, reset the bios, and reseat the cpu.

Now i'd put in the graphics card and no memory at all.

If cpu and mobo are still good, you should get a beep code error from not having any memory installed. (be sure you have a speaker connected to the mobo)

Not sure what messing up those power connections could do to a mobo, so it may not be functional.
But since you already turned it back on with the cpu and other parts installed, i would figure if it harmed the cpu, then the damage would already be done.

 

[jlharvison]

Thanks for the reply.

I will give it a try tonight.

To clarify, you are telling me that If I get the beep code for no memory, then the memory is dead, and the cpu and mobo is ok? Or is this test confirming only one of the two (cpu or mobo)?

 

[MTDEW]

No, dont put any memory in at all.

Be sure to reseat the cpu and heatsink, a bad seated cpu will cause a motherboard not to post and it will just sit there with fans running. (just as you described)

Now with no memory installed, if the cpu and motherboard are good, you'll get a beep code signifying a memory error.
Because there is no memory installed the mobo "thinks" you have bad memory and gives you the error beep.
You're just "tricking" the mobo to get a response to see if its still good.

If you get the beep code with no memory installed, thats great, then your cpu and mobo are good.
Install your memory and see if she posts.

 

[jlharvison]

Thanks for clarifying. I will perform the testing tonight.

 

[jlharvison]

I performed the test, and nothing changed. I ordered a cheap replacement board that I'll try next week. A buddy came up with some spare DDR400, so I'll also have that to try. If the cpu is dead, I'll just get a cheap replacement. I'm turning this box into a DVD/media player since my DVD player is on the fritz. I have already started ordering parts for a new main pc.

Thanks for the suggestions!