OBJECTIVES

2. OBJECTIVES 1. Demonstrate proper cleaning procedures for various system components. 2. Describe electrostatic discharge hazards and methods of preventing ESD. 3. List the steps for proper IC handling. 4. Define the term ground. 5. Describe the two types of uninterruptible power supplies (UPS) and state their qualities. 6. State typical precautions that should be observed when working on computer equipment. 7. Perform generic preventive maintenance routines as required (for example, remove excess toner, defragment hard drives, and create back-up copies). 8. Detail routine preventive maintenance procedures as they apply to hard and floppy disks. 9. Perform basic disk management functions on a hard drive, including using ScanDisk, CHKDSK, and Defrag utilities. 10. Use backup software to create backups of important data. 11. Use software utilities to identify and remove viruses from computer systems. 12. List precautionary steps that should be taken when handling floppy disks. (continued)

3. OBJECTIVES (CONTINUED) 13. List steps to clean a dot-matrix, ink-jet, or laser printer. 14. Establish and maintain preventive maintenance schedules for users. 15. Differentiate between various UPS specifications and state how they apply to a given situation. 16. State potential hazards that are present when working with laser printers, monitors, and other equipment.

4. Identify the purpose of various types of preventive maintenance measures, products and procedures, and when and how to use them. Content may include the following: Liquid cleaning compounds Types of materials to clean contacts and connections Non-static vacuums (chassis, power supplies, fans) Cleaning monitors Cleaning removable media devices Ventilation, dust, and moisture control on the PC hardware interior. (continued)

5. Identify the purpose of various types of preventive maintenance measures, products and procedures, and when and how to use them. Content may include the following: (continued) Hard disk maintenance (defragging, ScanDisk, CHKDSK) Verifying UPS (Uninterruptible Power Supply) and suppressors

6. Cleaning is a major part of keeping a computer system healthy. Therefore, the technician’s tool kit should also contain a collection of cleaning supplies. Along with hand tools, it will need a lint-free, soft cloth (chamois) for cleaning the plastic outer surfaces of the system.

7. TEST TIP Know the common methods of cleaning various computer components.

8. TEST TIP Know what types of materials/techniques can be used to clean different areas of the computer system.

9. Figure 8-1: How to Handle a PC Board

10. The environment around a computer system and the manner in which the computer is used determine greatly how many problems it will have. Occasionally dedicating a few moments of care to the computer can extend its Mean Time Between Failures (MTBF) period considerably. This activity, involving maintenance not normally associated with a breakdown, is called Preventive Maintenance (PM).

11. TEST TIP Know what environmental conditions or activities are most likely to lead to equipment failures.

12. TEST TIP Be aware of the effect that missing expansion slot covers have on the operation of the system unit.

13. TEST TIP Know that computer vacuums have special grounding to dissipate static buildup that can damage computer devices.

14. CHALLENGE #1 When you arrive at a customer’s office to repair one of their key computers, you trace the problem down to a defective microprocessor. The system has apparently been upgraded several times over its lifetime ¾ there are several open expansion slots and loose cables inside the system unit. There is also a layer of dust on all the internal components. What should you tell the manager when she asks you about what you have found?

15. Figure 8-2: Caution Areas Inside the Monitor

16. Figure 8-3: Proper Packing of a Hard Drive for Shipment

17. Figure 8-4: Data Backup Systems

18. TEST TIP Be aware of the precautions that should be employed with storing system backups.

19. Unlike hard-disk drives, tape drives, floppy drives, and CD-ROM/DVD drives are at least partially open to the atmosphere, and their media may be handled on a regular basis. This opens these drive units up to a number of maintenance concerns not found in hard disk drives. Also, the removable cartridges, disks, or discs can be adversely affected by extremes in temperature, exposure to magnetic and electromagnetic fields, bending, and airborne particles that can lead to information loss.

20. Figure 8-5: Cleaning the R/W Heads

21. Input peripherals generally require very little in the way of preventive maintenance. An occasional dusting and cleaning should be all that’s really required. There are, however, a few common-sense items to keep in mind when using an input device that should prevent damage to the device, and ensure its longevity.

22. TEST TIP Remember that dust can settle into the keyboard through the cracks between the keys.

23. Figure 8-6: Cleaning the Keyboard

24. Figure 8-7: Cleaning the Rollers in a Mouse

25. TEST TIP Know how to clean a trackball mouse.

26. Because printers tend to be much more mechanical than other types of computer peripherals, they require more effort to maintain. Printers generate pollutants, such as paper dust and ink droplets, in everyday operation. These pollutants can build up on mechanical parts and cause them to wear. As the parts wear, the performance of the printer diminishes. Therefore, printers require periodic cleaning and adjustments to maintain good performance.

27. WARNING Cleaning the printer and its mechanisms periodically adds to its productivity by removing contaminants that cause wear. Vacuum the inside of the unit, after applying antistatic solution to the vacuum’s hose tip. Wipe the outside with a damp cloth, also using antistatic solution. Brush any contaminant buildup from the printer’s mechanical components, using a soft-bristled brush. Never lubricate the platen assembly of the printer.

28. The steps to cleaning a dot-matrix printer are described in the following steps: 1 Adjust the printhead spacing. 2 Check the tension on the printhead positioning belt. 3 Clean the printer and its mechanisms. 4 Clean the printer’s roller surfaces. 5 Clean the surface of the platen. 6 Clean the surface of the dot-matrix printhead. (continued)

29. The steps to cleaning a dot-matrix printer are described in the following steps: (continued) 7 Clean the paper-handling motor’s gear train. 8 Apply light oil to the gears using a swab. 9 Turn the platen to distribute the oil. 10 Apply a light coating of oil to the rails. 11 Move the carriage assembly to distribute the oil.

30. The steps to cleaning an ink-jet printer are provided by the following steps: 1 Adjust the printhead spacing. 2 Check the tension on the printhead positioning belt. 3 Clean the printer and its mechanisms. 4 Clean the printer’s roller surfaces. 5 Clean the surface of the platen. 6 Clean the surface of the ink-jet printhead. (continued)

31. The steps to cleaning an ink-jet printer are provided by the following steps: 7 Clean the paper-handling motor’s gear train. 8 Apply light oil to the gears using a swab. 9 Turn the platen to distribute the oil. 10 Apply a light coating of oil to the rails. 11 Move the carriage assembly to distribute the oil.

32. TEST TIP Remember acceptable methods for cleaning laser printers.

33. Steps to cleaning a laser printer are described in the following hands-on activity: 1 Remove dust build-up, and excess toner, from the interior. 2 Clean the laser printer’s rollers. 3 Clean the paper-handling motor’s gear train. 4 Apply light oil to the gears, using a swab. 5 Distribute the oil throughout the gear train. 6 Clean the corona wires.

34. Check for other sources of heat buildup around the computer and its peripherals. These sources include: Direct sunlight from an outside window Locations of portable heaters in the winter Papers/books piled up around the equipment

35. Identify various types of preventive maintenance measures, products, and procedures and when and how to use them. Content may include the following: Verifying UPS (uninterruptible power supply) and suppressors

36. Avoid power variations ¾ Digital systems tend to be sensitive to power variations and losses. Even a very short loss of electrical power can shut a digital computer down, resulting in a loss of any current information that has not been saved to a mass storage device.

37. Typical power supply variations fall into two categories: Transients — an over-voltage condition, while sags are an under-voltage condition. Over-voltage conditions can be classified as spikes (measured in nanoseconds), or as surges (measured in milliseconds). Sags — can include voltage sags and brownouts. A voltage sag typically lasts only a few milliseconds, while a brownout can last for a protracted period of time.

38. TEST TIP Be aware of how undervoltage and overvoltage situations are categorized (i.e., time lengths).

39. There are two factors to consider when choosing a surge suppresser: Clamping speed Clamping voltage

40. TEST TIP Know what type of devices will protect systems from minor power sags and power surges.

41. TEST TIP Know what type of device prevents power interruptions that can corrupt data.

42. Uninterruptible power supplies are battery-based systems that monitor the incoming power and kick in when unacceptable variations occur in the power source. The term UPS is frequently used to describe two different types of power backup systems.

43. Figure 8-8: UPS System

44. Figure 8-10: Connecting the UPS in the System

45. NOTE High-power-consumption peripheral devices, such as laser printers, should not be connected directly to the UPS. These devices can overload the UPS and cause data loss.

46. If the UPS system does not come on, there are several items that should be checked. These items include: The On/Off switch The commercial AC power supply The UPS input circuit breaker The UPS battery connector

47. TEST TIP Remember that nonessential peripheral devices should not be connected to UPS supplies.

48. NOTE Of course, you should be aware that any UPS testing should be performed while the computer is not in active use and when there is no chance of data loss due to unexpected test results.

49. TEST TIP Be aware that the UPS system will not be able to control the operation of the computer without the serial communications cable installed.

50. TEST TIP Know that the best device for transporting computer equipment is the original manufacturer’s packaging, including the antistatic foam and bags used to pack it.