Refurbishing Personal Computers

Quick Status Check

When a batch of newly donated PCs arrives at our door, we first determine what works, and gather whatever info we can without opening the case. 

The CPU

By the way, we'll often refer to the case and its contents as a CPU, although technically the CPU, or central processing unit, is a matchbox-sized chip attached to the motherboard. In the first level or two of testing, we won't be opening the case. If and when you do, remember to detach the power cable while you're handling the components.

I like to stand a row of CPUs on their sides, all facing the same way, so that I can test them in assembly-line fashion. When it's time for the next CPU, I'll move one plug at a time directly to its new spot and power up before I worry about moving the tested unit out of the lineup. The testing process is so slow that I'm often running several testing stations at once, each with a line of CPUs.

The Monitor, a Lethal Weapon

Out of its protective case, the monitor is a very hazardous piece of equipment. Unless you're more expert than I, you should NEVER mess with a monitor's innards. Even after sitting idle for several years, a cathode ray tube has a sufficient charge that, if cracked, it could send shrapnel flying at an uncomfortable speed.

What's Written on the CPU?

On the front of the CPU case you will usually find

• Manufacturer's Name
• Model Name

On the back you will usually find

• Serial Number

On a sticker attached to the back you should find

• our in-house Inventory ID number

Label the Case

Your test results you should record on the case. I prefer to place a small label on the back of the case, because the back is the only part of the case that is never separated from the contents. Unfortunately, because the back of the case usually doesn't offer much space for a label, you can't say very much unless you write very small. If there is free space on the inventory label, you could use that. Label the right side of the case if you can't find room on the back. If you have no labels, a china-marker works well on painted metal cases.

Eyeball the Equipment

• Does the model name indicate that the machine is of the 286 or XT level? Label these and set them aside. If we use these at all, we'll leave the analysis to the experts and students of antiquity!

• Is there a 3.5" wide floppy drive?
• Many of the older machines we receive have only a 5.25" wide floppy. Label these as "Old" and set them aside.
• Some machines have both 3.5" and 5.25" floppy drives. These we will test.
• What type of connectors are on the back (occasionally side or front) of the case? Many of them may be lined up along the bottom of the case where the motherboard sticks through the back of the case. This section is mostly for your information -- it's not necessary for you to record findings on your label.
• Expect to find
• Power connector
• Keyboard connector, either a large 5-pin DIN or a small PS/2 type
• Video or monitor connector, a narrow female plug with either 3 rows of holes or 2. If it's only 2, label as "Old" and set aside.
• Parallel (printer) connector, a wide female plug with 25 holes
• One or two serial (communication) connectors, narrow 9-pin male and/or wide 25-pin
• You may find
• PS/2 mouse connector
• extra parallel or serial connectors
• If you notice the following, please indicate on your label:
• NIC (network interface card)
• sound card
• modem

Wire up the Equipment

• Attach keyboard, either a large 5-pin DIN or a small PS/2 type, to CPU
• Attach power cord to CPU
• Attach power cord to a VGA monitor
• Attach monitor data cable to CPU (the data plug has three rows of pins). If the CPU has no VGA plug (three rows of holes), label as "Not VGA" and set aside. If we use these at all, we'll leave the analysis to the experts.

Power On the Monitor

• Power on the monitor.
• Adjust the brightness and contrast only if you have trouble once the CPU is on.

Insert Boot Disk

• Insert into the 3.5" floppy drive a startup disk, labeled "DOS 6.22 Boot Disk." We usually use DOS version 6.22 for first-level testing of 386 and better equipment. On new 486 and Pentium equipment we might start with the DOS for Windows 95 (usually labeled "Win 95 Boot Disk").
• "Boot disk" is a broadly defined term. Technically, it means any "system" diskette -- one which includes the "internal" core of the DOS operating system. A diskette is large enough to hold the core plus maybe a third of the "external" DOS commands. When we say "Boot Disk," we'll be referring to a system disk to which we've added a selection of external DOS commands, plus a few other files.

Power On the CPU

• Power on the CPU. Do you hear anything? If not, label "No Response" and set aside.
• Adjust the monitor brightness and contrast if you have trouble seeing the display.
• You should see system startup messages appear on the screen.

Yes! System Boots from 3.5" A: Drive

• If the system starts normally from 3.5" diskette, you will be prompted to verify the date. Key in the correct date, or just press Enter if the date is correct. Verify the time.
• The DOS prompt A:\> should appear
• Record on your label "A: boots"
• Type MSD and press Enter
• Record the following on your label:
• Memory or RAM in rounded megabytes (MB). Example: 4096 bytes = 4MB
• Press D for Drive details:
• Record hard drive size in rounded megabytes (MB).

Congratulations! You're Done!

• Power off the CPU. Now hurry up and move all your cables to the next CPU and power it on. This is your only chance to save a little time! The rest of the testing process is an exercise in waiting.

What?! It Didn't Work?!

• ???

To Be Continued

• ...

Return to Previous Page

• Please press the Back button, or choose previous page menu option, in your web browser.

Return to Home Page

• Dave Butler's Rainforest Cottage at GeoCities

This page hosted by
Get your own Free Home Page