Hello! All members and visitors. Today i want share anything with you. That i know about Cell phone Repairing. If you are searching good based blogger for learn how to repair cell phone at home the you are right here. Happy to say after a long waited i have plan for teaching about cell phone repairing. Hope you enjoy these some tricks and techniques. As you know my wish, "Provide you a rich and unique contents" As my best knowledge base. I strongly request you to comments about my work. For improve my job i appreciate your suggestion. Thank you for visit "Let we stat"
Learn At Home, Complete Mobile Repairing now so easy
Before start our work i want share what kind of tools you have required for cell phone repairing. If you have a shop then no need any extra tools. But for new student must have access the following tools for testing and tracing cell phone faults.
- Solder wire / jumper wire and and heat gun with soldering element
- Board griper and tools kit
- Ct or petrol, Old cell phone PCB and some of accessories .e.g. charger, data cables software flashing devices, computer and internet
- Old cell phone dead motherboards for some parts replacing e.g. resistance/capacitor
- In the parts box basic most running parts of mobile phone e.g. mic,battery terminal,display(LCD),ringer,speaker,battery connector,charging base,sim jacket
- For Copying memory card, You need card reader
Cell Phone Categories by series are following:
In the market many cell phone models comes with different names. Every brand are labeled e.g. Nokia,Samsung,Q-mobile etc. After the cell phone name on front / behind the batter / on the inner there have model number e.g. Samsung Galaxy j-700 f. Every cell phone is comes in market by series, Some of most common series are following:
S-40 Series (Without java and application)
Some have java but many are without java. (Java is the software based facility that provide play games or software's) For example Nokia 1100,1110,1212,c-1 and other small price handset are comes in this categorize.
S-60 Series (With java or without java)
After success s-40 series Nokia have lounge s-60 series with more rams and user friendly browsing software. Nokia is the one of the best for easy and power full user friendly software, As known the Nokia logo hand set is the sign of quality and guaranty. In this categorize some most popular handset from Nokia company comes in past e.g. Nokia C-5, C-3, x-2-02 etc. (In these latest brands are comes with WiFi)wireless connection.
X series (Implicated WiFi, 3-G, 4G and Touch panel)
Is the series with WiFi and internet explorer for communication friendly and speedy some have 3-G or 4-G band.
Windows Series (Implicated WiFi, 3-G, 4G and Touch panel)
Latest by Nokia Company. Nokia introduce Windows cell phone with ios support implicated. Nokia Lumia is the best in this categorizes. Nokia 430,720 are my fave rte.
Android Series (Implicated WiFi, 3-G, 4G and Touch panel)
In these days this series is no-1 in all around the world. Many application are available and this series is touch and non touch used in many communicative devices. Tab, Note, Cell phone, Television, Camera, and many latest devices comes in the market with android version.
Understand, CELL PHONE PCB
Home for electronics parts, Where the all parts are paired by tree. There on every PCB or motherboard many parts are by series connected each others familiar. They called integrated in the following categorizes:
- Verb (Major parts on PCB) Example: IC (Integrated circuit) is the verb part of PCB
- Non verb (Helping Parts for major parts on PCB)Example:Resistance and capacitor are the helping parts for IC (Integrated circuit) on PCB
- Fuse and jumpers are for safety use in every electronics devices
- Resistance (Most common use in every electronics/electric devices)
- Capacitor (This is the most commonly used in every electronics/electronic devices)
Capacitor can store current for some moments, Some time during first startup cell phone or any device need full power to serve there work. For example Cell phone is powering on and searching signals and found every parts on PCB, There is full bright on display some or many applications are tuning together at startup. The all capacity of used for current is very high. You can check on auto voltage supply regulator display the pixel of used power supply are gone to 69 or above points. But when all processing of cell phone should complete and display lights are off from LCD and Keypad. The handset is off line and there on supply display show very low current in use. Cause for that the some very essential processing is running but most of the other processing should finished for max battery timing automatically.
At the testing pros Capacitor there have no rating for long time show a dial pad on multi meter.So after read all summery about capacitors, Now we collect some information to find on cell phone motherboard. Brown or white or black color is the symbol for capacitor. Brown is used for Stored current. and others colors are for frequency cycle control's. So the last word about capacitors are used for filtering and storing currents in every electronics and electric devices. In the cell phone every parts are micro categorizes.
- Fuse (This is the most commonly used in every electronics/electronic devices)
- From the main supply, Battery / charger is over current the fuse may have harm.
- From the water or rain shortage current, Fuse may have harm.
- From the old water damaged handset, Fuse may have harm.
- From the opposite connection of current e.g. negative probe connected on positive current, Fuse may have harm and device getting dead.
- From the shorted parts of cell phone, Fuse may have harm.
- Resistance (most commonly used in every electronics/electronic devices)
- Resistance should not boost any current from in to out points.
- Resistance can gain only high to low current.
- Resistance is the connection part of the pcb from one to another point.
- Resistance rating is by size and colour valuable.
- In condition of faulty this part hande set may have faulty.
- Transistor (most commonly used in every electronics/electronic devices)
- PNP (Base,collector,emitter) in this category the positive volts in on base point.
- NPN (Collector,base,emitter) in this category the positive volts in on collector point.
- It can boost or handle volts and frequency cycles.
- IC / Chip (Integrated circuit)
As a name integrated, Many electronics parts in one chip. The major part of cell phone processing unit. from the solid state physics converted some stages of electronics devices e.g. cell phone, camera, tv, computer into a one chip. The processor is a home of multi chips. In every cell phone the main chip (Processor) did not work without some helping parts. See this short menu of the chip for working:
- IC: In the cell phone PCB, the major part is a main chip.
- Helping parts e.g. resistance,capacitor and transistor are the pre versions of main chip.
- Some cell phone used a single chip with build on flashing, signal, Sound etc. but some have independ chip for the signal, flashing and sound etc.
- In condition of faulty chip the chip should warm up after few second power on the cell phone. This chip is warming up from the many reasons, Shortage stage of inner in chip / outer on PCB. Example: Main chip is warm up, In the main chip circuit may be the charging,signal,sound or any stage is faulty for cause of warm up the chip.
- From outside the supply is over current, during processing some helping parts may have harm. For the conform is their main chip is faulty, Please be carefull. Trace or check before replace or remove main chip. May be some other reasons are involve to heat up the main chip. e.g. ringer connection are shorted with ground directly.
- Power chip, Controller chip for the supply. If faulty, the Handset did not power on or shortage and battery timing is so short.
- Signal chip (PA), The signal stage controller chip. If faulty, there is no signal or weak signal in cell phone.
- Flashing chip (ROM), Storage drive for cell phone software. if faulty handset did not power on, Some time flashing the lcd and some time hang on LOGO.
- Sound chip, Sound controller stage. if faulty there is no sound in ringer.
- Bluetooth chip, BT Communication chip controller. If faulty there is no access in search neighbor bluetooth device.
- Display chip, Display controller for lcd data. If this chip is faulty, there is no display,scrambled display, white display or blank display on the LCD.
- Keypad Chip, Keypad controller chip. If faulty there on keyboard some or all keys are missing. Keypad did not work correctly.
- What kind of components that should jumpering by diagrams
- Keypad chip (Make directly jumper on missing keypad tracks from one by one)
- Signal chip (Low signal problem occurred by using the jumpering in some cases)
- Fuse (Burning or missing fuse we should directly jumpering from one to another point)
- Resistance (We can direct some types of resistance on the PCB)
- PCB broken links (From one point to another point we can make a jumper)
ANDROID CELL PHONE HARD RESET WAYS
When cell phone start hanging, Slow on speed or any application issu. You need to an hard reset your cell phone for the default settings. There are some differents ways to do this action. Here are some hard reset tricks for help to reset your cell phone.
- Hard reset cell phone from the setting menu (Factory setting)
- Factory setting
- Give the password
- 12345 (Nokia)
- 1122,1112,1234,0000,2233 (Android / China)
- Hard reset cell phone from the power on (Factory setting)
- Hold on volume up key then press power on button
- Hold on volume down key then press power on button
- Hold on both volume up and down key then press power on button
- Hold on Home plus volume up key then press power on button
- Hold on home plus volume down key then press power on button
- Hard reset cell phone with the flashing device (Factory setting)
- Connect your cell phone with the device data cable
- Open flashing software of the device that you have set up in your computer or laptop
- Go to the factory default panel and click to continue
DISPLAY PROBLEM AND THEIR SOLUTION
Due to rain, water damage or missing broken links are cause of this problem commonly in every cell phone. The broken display solution can solve only with new or working display. But in many time from the troubleshooting of cell phone PCB points i solve these problems:
- White display (Change LCD or check lcd connection from the connector)
- Blue display (Check connector)
- Scrambled display (Check connector from the both sides LCD/PCB)
- Blank display (Check connectors, Change LCD)
- No lights on the display (Check LED lights, Volts and connection)
SIGNAL PROBLEM AND THEIR SOLUTION
When signal stage is faulty the cell phone signal should gone or low. You can not make a call to another cell phone or during call the sound like as fax machine. In the many cell phone i see the signal baar with the one or two points. In this situation, when the cell phone our range from the tower. There is no signal. Anyway see here are the most commonly signal problem solution:
- Low signal (Check antenna)
- No signal (Heat, change PA)
- Signal OK but call failed (Check RX or TX of signal chip or change signal chip)
INSERT SIM PROBLEMS AND THEIR SOLUTION
When insert sim option show on the screen of cell phone after inserting sim in sim tray. This mean this sim stage is faulty of the cell phone. Some time the sim chip is broken cause behind this error but many time i see this problem in sim jacket or connection. So here are the troubleshooting guide for possible solution of insert sim error.
- Check / change the sim side and cell phone side connection (Both clean and scratch for the carbonyl issue)
- Check the sim jacket points (One point is always ground and in many cell phone the one point is empty) If missing any connection please make jumper.
- Check Sim chip (Some time broken or carbonyl chip connection are the major cause) Change the sim controller chip, Heat or make jumpering on it.
CHARGING PROBLEM AND THEIR SOLUTION
Charging error starts in many cell phone from the USB bad connection. There is no option at connect the charger on the screen. But many time i see the charging volts getting wrong rating on the positive point of battery terminal. Here are the possible solution of charging problems: