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PowerTalk

Tales of Trials by Fire!
September 2002

Shane Hicks is an independent consultant and technical trainer, providing support to individuals and small businesses. He's been in the industry for over 10 years.

Email your questions, it will be answered as space permits.


I heard the voice on the other end of the phone say, “My computer blew up.” 
My response:  “Why do you think this?”
“The monitor started smoking and we ran out of the room. Now it won’t turn on.”
I said optimistically (or was it foolishly), “Well, if the smoke was coming from the monitor, it might not be that bad. Bring it to me and we’ll see what we can do.”

I opened the case, which looked fairly clean inside, and plugged it in. Nothing happened when I pushed the power button. “The smoke came from the monitor — right?” Feeling brave, I swapped power supplies. This time, the computer responded — with flames that leapt from two chips uncomfortably close to the processor! The smoke was not coming from the monitor.

I gutted the case and installed a replacement motherboard. When I pulled the processor and fan from the old motherboard, I discovered they’d become quite attached to each other over time. Since breaking this bond can render the heat sink fairly worthless (without significant reconditioning), and could damage the processor, I decided to hope for the best and leave them together.

I applied power and the fan started spinning, but nothing else happened — no beeps, no video. Figuring the processor was fried, I pried the fan off and surveyed the processor’s charred top. Pulling a doppelganger (my wife’s new favorite word) from stock, I replaced the crispy critter. The cheery beep of POST greeted me, and the monitor came to life. With this, I was pleased to discover that the video card and memory from the old system seemed to have survived. I connected the floppy and quickly arrived at a DOS prompt via the Windows 98SE start disk.

The hard drive came next, but the scan of the bus failed to find the drive. After checking the connections, I placed my hand on the drive and rebooted. The drive was silent and motionless — another casualty. With a new hard drive in place, it was on to the CD-ROM. I wasn’t optimistic with its chances, since it had been on the same cable as the hard drive. The power light came on, but nobody was home. The drive motor wouldn’t spin and the tray wouldn’t open.

I decided to load Windows next, to better test the memory, the video, and then the other expansion cards. The operating system installed without error, so I moved to the modem. This card appeared healthy on the outside, so I placed it in the last PCI slot and turned the computer on. The modem came up and was soon screeching that familiar sound of going on-line. The sound card was not so lucky. A major crack was visible on one of its primary chips — the normally green PCB around the chip was charred where portions of the chip had melted. Adding a new sound card, and placing a NIC which was removed from the old system before the power spike, on the motherboard completed the restoration. A few drivers, a few reboots, and a series of Window’s updates later — the computer was restored to life.

So, what morals can we learn from this story?

  1. The time to invest in a good surge protector is not after a huge storm hits town. Make the investment up front to avoid the pain and suffering in the end. I always recommend APC surge protectors and UPS devices.

  2. When the time comes to test a new processor on a motherboard, do not forget to put the heat sink in place and plug in the fan. Modern processors can overheat in less than a second, and will not give you time to see the POST before they overheat for good.

  3. Do not reuse old heat sinks without cleaning the surface that touches the processor and replacing the padding. Forming the proper bond between the processor and heat sink is crucial. Apply heat dissipating grease as necessary, but do not over use it. This grease can actually cause a short circuit on processors where the core is exposed on the top.

  4. It’s always good to have a Windows 98SE start disk. This disk contains generic drivers for accessing nearly any CD-ROM drive and also provides tools for formatting and repairing hard drives. This is a critical tool when diagnosing and rebuilding systems.


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