Page 75 - Electronic Mechanic - TP - Volume - 2

ELECTRONICS MECHANIC - CITS

SIM IC

This IC is used for controlling SIM card data. when it is damage you can see following faults. This is a crystal IC
because of that when fallen down your phone like this IC will be damage easily. Therefore we can say following
faults are common faults in nowadays.

i Insert Sim
ii Unable to power on with sim card
iii Sim not accepted.

Key Pad IC
This IC is used for Controlling Key pad circuit. We can see this IC as crystal and normal type. because of that
when fallen down your phone like this IC will be damage easily. Therefore we can say following faults are common
faults in nowadays.
i Key pad not work as a order
ii Key pad stuck
iii When power on one key is dialing continuously

iv When press a key phone will shut down or restart
v Keypad work as a unconditional
LCD Light control IC
This IC is used for controlling keypad and LCD lights. We can see this IC as crystal and normal type. when this is
damaged we can see following faults.

i Key pad lights not work
ii LCD lights not work
iii White Display
iv Display not work

When you see like above damages don’t try to do remove that ICs. Because there have a method for solving any
faults in mobile phone. Therefore firstly try to understand about mobile phone ICs and about its works and also
damages.
Hot Air Blower: It is also called SMD (Surface Mount Device) rework system and SMD repair system. It has control
to regulate or manage temperature and flow or hot air. Always buy a good quality ESD-Safe hot air blower.
Figure Hot air blower.

The hot Air blower used to de-solder and solder the Ics of Mobile phone.
The hot air is blown at Ics to be removed.

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CITS : E & H - Electronics Mechanic - Exercise 134