Observation

This question seeks to test candidates’ practical knowledge of the course. The performance of candidates that attempted this question was fair indicating their lack of exposure to the practical aspect of the subject.

The expected answers are:

(a)          Causes of mobile phone signal problems

• Antenna not having good contact with board
• Bad Antenna switch
• Band filter may be bad
• RF may be bad
• Antenna socket may be bad
• TX or RX filter may be bad
• Resistor, capacitor or coil may be bad
• CPU may be faulty
• Bad network IC
• Phone settings problem

(b)          Solutions to the causes identified in 11(a)

• Antenna not having good contact with board: re-align or change it
• Antenna switch may be bad: Replace it or run a jumper
• Band filter may be bad: Replace it or run a jumper
• RF may be bad: replace it or run a jumper
•  Antenna socket may be bad: replace it
• TX or RX filter may be bad : Replace it or run a jumper
• Resistor, capacitor or coil may be bad: Replace it
• CPU may be faulty: not replaceable
• Bad network IC: replace it or run a jumper
• Reset to default phone settings