๐ฒ Dial *#06# on your phone's keypad to instantly display your device's IMEI number.
โ Works on Android, iPhone, and most feature phones.
๐ก Tip: Save your IMEI somewhere safe โ it helps track or block a lost/stolen device.
โ๏ธ Engineering Codes
Correct dialer codes by model
Brand
Code
Main use
๐ ฐ๏ธ Samsung
*#0*#,(mic test:*#0283#)
Hardware test menu
๐ญ Xiaomi / Redmi / POCO
*#*#6484#*#*
CIT hardware tests
๐ข OPPO
*#899#
Engineer/diagnostic mode
๐ก Realme
*#899#
Engineer/diagnostic mode
๐ด OnePlus
*#808#
Manual hardware testing
๐ต Vivo / iQOO
*#558#
Factory/hardware test
๐ก Motorola
*#*#2486#*#*
Hardware/CQATest
๐ธ Huawei
*#*#2846579#*#*
Project/engineering menu
๐ Honor
*#*#2846579#*#*
Engineering/project menu
๐ฎ Sony Xperia
*#*#7378423#*#*
Service/diagnostic menu
๐ป ASUS
. 12345 += in Calculator
Hardware test on supported models
๐ป TCL / Alcatel
*#2886#
Hardware test on supported models
โก ZTE
*983*3641#
Hardware functional test
โช Nothing
Limited/model-dependent
No universal hardware code
๐ Google Pixel
*#*#4636#*#*
Phone/testing information
๐ฆ Nokia
*#7370#
Soft reset / factory reset menu
โ ๏ธ Codes can vary slightly by software version, region, and carrier. Some menus can change device settings โ proceed with care. Always double-check the exact model before using a hardware test option.
๐ Mobile Number Check Code
Find your own SIM number
SIM
Code
๐ต Jio SIM
1299
๐ถ Other SIM
*121*2#
๐ฒ Dial the code above (as a call) on the SIM you want to check โ your own mobile number will be sent back by SMS or shown on screen.
โ ๏ธ Codes may vary slightly by circle/region and can change over time as per operator updates.
๐ฉ Motherboard Parts
5 basic mobile PCB components
๐ซ Resistor
A small component that limits or controls the flow of electric current in a circuit, protecting sensitive parts from too much power.
On mobile PCB: Controls current to LEDs, sensors & small ICs. Identified by colour bands or SMD codes (e.g. "103").
๐ Eppadi kandupidippathu:
โข Pin: Two pin erugum
โข Center: Mala (black) alladhu Blue colour block
โข Pin side: Two pin-laum mala (black) iron erugum, side-la vera colour erugum
๐งช How to check a resistor (multimeter): Safety: Disconnect power and the battery before testing. Safely discharge any capacitors.
โข Setup: Set the multimeter to resistance (ฮฉ) mode
โข Test: Touch the probes to the resistor's two pins. Other parts on the board can affect the reading; lift one resistor lead if needed for an accurate check
โข Result: Compare the reading with the resistor's rated value and tolerance. If it is outside that range, investigate further. OL may mean an open resistor, poor probe contact, or a value above the meter's selected range
โข Beep: No beep alone does not mean a resistor is faulty. Continuity mode only beeps below the meter's resistance threshold
๐ Coil (Inductor)
A coiled wire component that stores energy in a magnetic field and smooths/filters current, especially for power supply lines.
On mobile PCB: Found near charging IC & power management IC. Often a small square/round metal-shielded block.
๐ Eppadi kandupidippathu:
โข Pin: Two pin erugum
โข Center: Mala (black) colour block
โข Pin side: Two pin-laum mala (black) iron erugum, side-laum mala (black) colour erugum
๐ต Condenser (Capacitor)
Stores and releases small amounts of electrical energy, used to smooth voltage and filter out noise from the power line.
On mobile PCB: The most common part โ tiny black/tan SMD rectangles all over the board, near battery & IC pins.
๐ Eppadi kandupidippathu:
โข Pin: Two pin erugum
โข Center: Mala brown colour erugum
๐บ Diode
Allows current to flow in only one direction, protecting the circuit from reverse current and converting AC to DC in some paths.
On mobile PCB: Used in charging circuits & battery protection paths. Small black component with a band marking direction.
๐ Eppadi kandupidippathu:
โข Pin: Two pin erugum
โข Band: Adi-la (bottom side-la) oru kodu (line/band) erugum
โฌ IC (Integrated Circuit)
A chip that packs thousands of tiny circuits together to process signals, manage power, or control specific functions of the phone.
On mobile PCB: Includes CPU, power management IC (PMIC), charging IC, audio IC, Wi-Fi/RF IC โ the "brains" of the board.