GSM Phone Maintenance and Repair Paper 2, WASSCE (SC), 2019

Question 13

Identify Figs 1 and 2
1. Fig. 1;
2. Fig. 2.
State one advantage of
1. Fig.1 over Fig.2.
2. Fig.2 over Fig.1.
State two precautions that should be taken when using Fig.2.

State the principle of operation of the device in Fig. 3
List two substances that Fig.3 can be used to remove.
Which mobile phone component is cleaned using Fig.3?
State one precaution that should be taken when using Fig.3.

Identify:
Fig. 4;
Fig. 5.
What class of tools do Figs.4 and 5 belong?
State the function of Fig.5
Give two reasons cotton is a better raw material for making Fig.4 than nylon

Observation

Most candidates attempted this question and the performance was good. This is due to increased awareness of the subject, engagement of qualified personnel to teach the subject and more exposure of candidates to practical work.

The expected answers are:

Identification of Figures
Fig. 1: Power bank / UPS
Fig. 2: Generator

1. Advantages of Fig. 1 over Fig. 2
  - It is portable
  - Inexpensive to maintain
  - Stores energy for later use
  - It is cheap to procure
  - It is environment friendly / does not cause air pollution
2. Advantages of Fig. 2 over Fig. 1
  - It can power other appliances while in operation
  - It is stationary and cannot be misplaced
  - It can supply power for a longer period

Precautions that should be taken when using Fig. 2
- Do not approach with naked/exposed fire
- Avoid smoke while starting or fuelling it
- Do not touch the exhaust while in operation or immediately after use
- Do not refuel while in operation
- Avoid the use of electronic devices while fuelling it
- Turn off all connected appliances before putting it on
- Do not touch Fig.2 when in wet conditions
- Check to ensure there is no fuel leakage before use

Fig.3 uses the principle of ultrasound to perform its operation

Substances that can be removed using Fig. 3
- dirt
- dust
- liquid

The mobile phone component cleaned using Fig.3 is the PCB

Precautions that should be taken when using Fig.3
- remove all delicate parts before putting the PCB in the cleaner
- ensure it is operated according to its operational instruction
- do not use mineral acid as cleaning fluid
- do not use flammable solutions as cleaning fluid
- suspend items to be cleaned in the equipment

Fig. 4: Antistatic hand gloves
Fig. 5: antistatic wrist strap

Figs. 4 and 5 are classified as safety tools

Fig. 5 protects components from electrostatic charges

Reasons cotton is a better material for Fig.4 than nylon
- Nylon gloves will melt when exposed to heat
- Nylon gloves cannot be reused
- Sharp objects will easily penetrate the nylon material