COMMON PROBLEMS OF MOBILE CELL PHONES AND THEIR REPAIR.

COMMON PROBLEMS OF MOBILE CELL PHONES AND THEIR REPAIR: The following mobile cell phone problems with their repective repair solutions were discussed.
(1) Mobile cell phone power problem and repair.
(2)Mobile cell phone ringer problem and repair.
(3)Mobile cell phone vibrator problem and repair.
(4) Mobile cell phone ear problem and repair.
(5) Mobile cell phone keypad problem and repair.
(6)Mobile cell phone mouth piece problem and repair.
The remaining problems will now be discussed i.e:
(7) Mobile cell phone locked problem and repair.
(8) Mobile cell phone tripping problem and repair.
(9) Mobile cell phone malfunction and repair.
(10) Mobile cell phone network problem and repair.
(11) Mobile cell phone charging problem and repair.
(12) Mobile cell phone screen problem and repair.

MOBILE CELL PHONE LOCKED PROBLEM AND REPAIR
Various security measures could be put in place by a network provider to prevent their mobile cell phones which are usually subsidized/given on contractual payment terms to their customers from being used in other networks.These measures include simlock,waplock,keypadlock etc.The cell phone can only use the simcard of the provider in question.Pincode,PUKcode and security codes are built in to enable the cell phone owner control the use of the mobil cell phone and prevent usage by unwanted persons.Most of these locks can however be removed by a smart unlocking software.
MOBILE CELL PHONE TRIPPING OFF AND REPAIR.
This problem can be solved by :
(1) Make sure the battery is well charged.
(2) Clean the battery contact.
(3) Ensure that the connector contact with the PCB.
(4) Resolder the entire PCB by heating with hot air from a rework station.
(5) Clean/wash with methilated spirit/volatile liquid and dry with the blower.
If these fails, flash the mobile cell phone with the appropiate flash file.

MOBILE CELL PHONE MALFUNCTION AND REPAIR.
(1) Resolder all ic on the panel
(2) Wash/clean the pcb with brush and methilated spirit. Dry with a blower.
(3) If problem not solved flash the cell phone.

MOBILE CELL PHONE NETWORK PROBLEM AND REPAIR.
(1)Clean the surface of the sim card.
(2) Clean the sim card reader surface.
(3) Make sure the antenna makes proper contact with the PCB.
(4) Heat the entire PCB with rework station to resolder the ics
(5) Flash the cell phone .Note that if there is no network at all when power is switched on,the problem is likely from the antenna switch.

MOBILE CELL PHONE CHARGING PROBLEM AND REPAIR.
(1) Charge the mobile cell phone with another working charger.If this charge the mobile cell phone, replace the charger.
(2) Re-solder the charging pot and make sure it contact with the PCB.
(3)Use a desktop charger for your cell phone if the damage is beyond repair.

MOBILE CELL PHONE SCREEN PROBLEM AND REPAIR.
(1) Check for physical damage on the screen. The screen could be broken. Relplace.
(2) Check screen connector to PCB or theflex. ensure proper contact.
(3) Heat the PCB with rework station to re-solder the various components.
(4) Clean/wash the PCB with methilated spirit and dry with blower.
Replace screen or flash the cell phone.

MOBILE CELL PHONE SOFTWARE PROBLEM AND REPAIR
When one or more of the three basic faults of the electronic components of the mobile cell phone ie Open circuit,Short circuit or circuit leakage cause distortion \in the programming of the eeprom area of the mobil cell phone, a software problem result." Contact Service" problem is a well known example.Software problems result in the malfunctioning of the mobile cell phone. It could affect the powering of the cell phone,cause network problems, screen problems,phone tripping off,cause the keypad to malfunction etc. Software problems are solved by flashing the mobile cell phone with the appropriate flash file.

N.B. In the next post, we intend to look at other mobile cell phone problems experienced by users but not so far discussed.

Godak.