Un-“Beeping”-Believable

Tracking down hardware issues can be challenging sometimes…

About 5 or six months ago I decided to fix some stability problems with my son’s computer. It was blue screening during heavy 3d gaming. I had run some basic diagnostics and found that it was failing certain extended memory tests. So I decided to buy a new DIMM for the machine, and since the case I was using was ridiculously loud, I decided to buy a quieter case at the same time.So I move all the hardware to the new case, and it boots right up. I run the same memory tests, and they all pass. I play some games for a few hours, and satisfied that it is no longer blue screening, consider it a job well done.

A month later, my son comes in and tells me “The computer is not working…all I did was shut the door on the front, and it powered off. Now it won’t turn back on.”

So, I troubleshoot it for a while. I can get it to boot sometimes and it never runs for more than a few minutes. Most of the time, it fires up for 2 seconds and immediately powers off.

After unhooking all but necessary hardware and having the same results, I decide it must be a bad power supply. I buy a new one and install it…same exact symptoms…power on, fans spin up for 2 seconds and power off.

I know think to myself, it must be a bad motherboard. I begin a 4 month search in vain for the same model motherboard. I wanted to find the same one so I would not have to deal with installing different drivers or reactivating XP, plus I would know all my other hardware should work fine. I found several on Ebay and other classified ad sites, but could never succeed in closing the deal at a price I was willing to pay for a 4-year-old motherboard.

I finally convince a friend of mine to sell me a motherboard/cpu combo he was hanging on to to build a spare machine of his own. Two nights ago, I installed that motherboard/cpu in the case, and it boots successfully the first time. I’m relieved and getting ready for a night of installing software and drivers, etc. I immediately go into the BIOS to reset to defaults and configure the hard drives and such, and right after loading the optimized defaults, it powers off.

I figure its a fluke, somehow related to the optimized defaults not the ideal choice for my particular hardware. So I power it back on…and it dies in 2 seconds just like the other board.

I nearly screamed.

So I figure, some other piece of hardware is the problem. I unhook everything but the CPU, and it boots fine. I started adding things back one at a time, and it keeps booting fine until finally I have everything hooked up. I had decided to move the DIMM to the last slot instead of the first during that process (to have it further from the CPU), so I figure that is what the problem was. Maybe the new RAM I had bought months earlier was simply bad. Different motherboard/CPU, and same problem.

So last night, I am running some more tests to confirm stability, and finally recognize that I am not hearing a “beep” after the POST. I obviously forgot to hook up the speaker. So, I hook up the speaker, and the thing won’t boot! I nearly fell out of my chair. I unhooked the speaker and it boots right up.

So, long story short, it all makes sense now. When my son closed the door on the case all that time ago, something moved inside the case and created whatever short there is in that speaker circuit.

I took the case apart, and found that the switches and LEDs are held in by some silicone glue. There was a strand of glue running across the back of the speaker that reached all the way to the back of the power switch, and across to the reset switch. I broke the strand, hooked the speaker back up, and everything worked fine. Silicone in that form is not supposed to conduct electricity, but clearly was shorting out my motherboard somehow.

It floored me. I have never seen anything like it in my 19 years of working with computers.