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Microcomputer care and repair.

This series of articles aims at providing enough non-technical information to help microcomputer users minimize downtime and repair expense and avoid injury when troubleshooting.

Here in the first article I will deal with preventive maintenance, safety, and inventory. Next month, I will discuss troubleshooting.

You may have taken chemistry or hematology analyzers apart, cleaned contacts, and substituted circuit boards-while hesitating to do the same on your microcomputer. Don't be intimidated. The devices may differ, but the digital circuits are essentially the same, and the basic procedures for care and repair apply to any system.

* Prevention. You can prevent failure in microcomputer operation through a number of good practices. Diskettes, for example, are extremely important to the system and should not be abused. Always store them upright in their jackets-arty or warped diskettes can damage disk drives. Use a felt tip marker when labeling to avoid denting the diskette. Make backup copies of data disks and store them in a different location.

Then there are the things not to do. Never bend or fold a disk; never touch the disk surface; never slam the disk drive door on a diskette or jam a diskette into the drive; never subject a diskette to extreme temperatures; and never put diskettes near monitors, TV sets, speaker systems, coiled wires, telephones, calculators, or any other magnetic field. Even though industry experts say it is not a problem, many computer users also do not let their diskettes pass through airport x-ray monitors or magnetic theft detectors.

Make sure a disk is in the drive before closing the door. Closing a double-sided disk drive door without a disk inside can chip the heads. Also, never transport a disk drive with the door open. Insert a scratch diskette (one with no longer needed information) or the diskette's original cardboard shipping protector, and close the door.

A hard disk dfive should be parked when moving the computer, to avoid damaging the heads.

Here's a suggested schedule for periodic maintenance:

Once a week, clean the housings and cases and display screen with the proper anti-static solutions.

Once a month, vacuum the inside of the computer and printer. If the equipment has filters, check them for dust. Also check connector cables for corrosion. Make sure that the screws fastening the cables to the sockets are ghtly i place and the cables are not stretched so tightly that any jolt would disconnect them.

Every three to six months, use a diagnostic disk on the computer to uncover problems with system boards, memory, the keyboard, the printer adapter, the monitor, the graphics card, and other aspects. A self-test that comes with some printers can also detect problems.

The diagnostic routine should not be used for hard drives (there are special routines for these) but can be used to check floppy diskdrive speed and head alignment.

Cleaning the drives every six months is adequate even for heavy usage. Clean them more frequently if smoking takes place near the computer (no one, of course, should smoke in a laboratory).

A mini-vacuum cleaner, to remove dust and lint inside the microcomputer and printer, is an important maintenance tool. There are also specific cleaning solutions for glass screens, glare-free screens, and the outside case of the microcomputer. Disk drive heads may be cleaned with long swabs dipped in 70 per cent isopropyl alcohol or a diskette headcleaning kit.

Wipe with lint-free rags. Make sure ventilation holes are not clogged or obstructed in any way. Use pipe cleaners for places that are hard to get at, a non-abrasive pencil eraser to clean contacts on the edges of boards, a Teflonbased lubricant (such as Radio Shack's Break Free) to clean contacts on the monitor knobs, and canned inert gas to blow out lint from places a vacuum cleaner can't reach. Never use compressed air for lint removal-it will leave moisture.

Check the manufacturer's manual for any other special cleaning instructions.

The monitor screen's life can be prolonged through a screensaver program, which automatically turns off the screen if you have not touched it in a certain length of time. As an alternative, you can turn the brightness switch down if you will be away from the computer for an extended time.

* Safety. Think. Analyze the situation before jumping in. Do not reach into energized equipment. Before going into the chassis of the computer or printer, turn off the power, ground yourself (discharge static electricity) by touching something else made of metal, and unplug the cord. Persons passing disks to each other should also ground themselves; otherwise they risk losing some data.

Respect electricity. At I milliamp (0.001 amp), a shock can be felt. At 10 milliamps (0.01 amp), muscles become paralyzed, and you can't let go. At 100 milliamps (0.1 amp), a shock lasting more than one second can be fatal.

The most dangerous elements-like wall outlets, power cords and switches, power supply, and monitors-are well protected except at connection points. A monitor, which you should never open, can have a few thousand volts if it is black and white, 25,000 volts if it is color.

Use only insulated tools. Select the right tool for the job and apply it properly.

Remember that jewelry can be hazardous. Rings, bracelets, and necklaces can cause short circuits or get caught in mechanical parts. Long hair can also become entangled in machinery.

Besides insuring personal safety, try to protect the computer from injury. Keep liquids away, especially from the keyboard, and do not drop anything inside the chassis. Before powering up, account for all screws and parts you may have been working with. Treat every component of the computer gently; do not use force.

The computer is well designed. If you are having trouble removing or replacing anything, check to see if anything is in the way.

Always ground yourself before touching a computer chip. The CMOS chips (marked with a fourdigit code beginning with the number 4) are susceptible to static electricity. Visual inspection of a chip will detect only bent or broken pins, not a short circuit.

*Inventory. You should have a complete written inventory of hardware and software, along with documentation (manuals), whether you have one microcomputer or 50. An inventory is necessary for insurance purposes, and it has other important uses.

A good inventory list will indicate if there is another user in the laboratory or the hospital who can give you some insight on hardware or software problems. When a desirable new version of existing software becomes available, the list will tell you how many copies have to be updated.

Before buying an item, check the inventory list to see if anyone in your organization has something similar. You may be able to get feedback on how well the item works, see it in action, and even try it. Someone else may have a good alternative. And if you have just damaged a program disk or suspect that a piece of hardware is malfunctioning, you have quick access within the organization to a replacement for trial substitution.

About 80 per cent of all computer failures can be attributed to operator error. Documentation contains helpful information, such as switch settings, answers to problems, and schematics.

The hardware list should include the location of each computer. Do not record the name of the person using it. He or she may leave or someone else may be assigned to the system. Note the type of hardware, serial number, where it was purchased, dates of installation and repairs, memory installed, number and type of disk drives, monitors, peripherals, and option cards. The inventory should list all available infomiation about each component in the computer.

If you have a service contract, note its number, the vendor's name, and the name and phone number of the contact person.

The software inventory should include the type of program, its name, the version, whether or not it is licensed, and the number of copies and their location.

All documentation of hardware and software should be filed in one place and copies kep with each computer.

As for an inventory of spare parts, an easy way to build one is to buy two replacements instead of one every time you have to change a part. Keep a list of available spare parts. Repair or dispose of any defective items-it is frustrating to think you have a replacement and find that it doesn't work.

This discussion has left us poised for troubleshooting-a subject we will take up in next month's issue. n

General references:

Alvernaz, B. "Expanding Your IBM PC--A Guide for the Beginner." New York, Brady Computer Books, 1984.

Boston Computer Society. "Things the Manual Never Told You-IBM PC Edition. " Reading, Mass., Addison-Wesley, 1985.

Williams, G. "How to Maintain and Repair Your IBM PC." Radnor, Pa., Chilton, 1984.

Zaks, R. "Don't (Or How to Care for Your Computer)." Alameda, Ca if., Sybex, 1981.
COPYRIGHT 1989 Nelson Publishing
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1989 Gale, Cengage Learning. All rights reserved.

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Title Annotation:part 1
Author:Schneider, Nancy Dankes
Publication:Medical Laboratory Observer
Date:May 1, 1989
Words:1481
Previous Article:Strategies for dealing with AIDS in the laboratory setting.
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