How to Check Parts of a Mobile Phone for Fault

Santosh Das

Santosh Das

Santosh is an Electronics Geek, Blogger, Young Entrepreneur and Founder of this Mobile Phone Repairing Website. Santosh possesses vast experience in the field of electronics, telecommunication, Soldering, SMT, ESD Safety, PCBA Tools & Equipment. Keep visiting for daily dose of Tips and Tutorials.

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162 Responses

  1. Avatar Jacob Amponsah says:

    how to replace a capacitor and resistor on a samsung phone

    • Santosh Das Santosh Das says:

      Most Technicians just don’t bother to replace the Tiny SMD Capacitors and Resistors. They just remove them using soldering iron and the phone works fine. But if you can get the Capacitor and resistors then replacing is easy. Just desolder the faulty ones and replace with New ones using solder paste and hot air blower.

  2. Avatar Hope says:

    Gionee gn 5001s switched off after the battery went 0%.I tried to charge it but it didn’t charge and so never turned on.and I have also boost the battery but same problem and I have changed a new battery but same problem. Leaving the battery for long inside the phone will completely drain the battery but still not power on. I need help

  3. Avatar siraj says:

    Network IC: Use a Analog DC Power Supply to check Network IC. Switch ON DC Power Supply and call any number from your mobile phone. The Needle of the DC Ampere will start moving. This shows that the Network IC is OK and not fault.

    i didnt understand..

  4. Avatar Harilash says:

    Hi sir I have Micromax AD4500, I check that no short and also cheked on /off switch voltage all are good but still it dead please help me sir how to solve pls

  5. Avatar Pasha says:

    Hello sir my self pasha.
    Sir m seeing some mobiles are same problem only red light blinking phone r totally dead when i was chehk hard ware its ok software also ok but mobile phone totaaly dead how can i deduct the problem

  6. Avatar chiranjit Das says:

    Mother board.. Is totally in good condition …no short ..but not getting switch on. …..battery OK.. . ..any solution

  7. Avatar Aj says:

    I Have given phone to repair in one big company and not service centre
    as service centre told that PBA/Front camera/ and charger ports is damaged due to water and it is not covered under warranty so they have given repalce cost of 17000/- of c9pro
    and one company claims that they repair motherboard and it doesn’t require to replace so i gave the phone to them
    now the company after taking phone for repair call back me for screenlock code and open phone and said phone started but after someday when they didnt return phone i call back and ask for phone they said phone display not working and spcb not working
    so my question why they taken the screencode and said phone is ok
    2 the samsung service centre said the pba is damaged and not the display then now how display is damaged
    so when they return my phone back they didnt repair and send me back as it is but without display and i didnt accept it as there was no display in it
    afterwards they again return my phone with display biut there were scratches on it which doesnt belong to me
    so now how can i check whether the display belong to me is there any mark or identification no on display to check with imei of phone
    please help me out how to check it

  8. Avatar sadanio says:

    Thank you for this helpful Article
    I have my Samsung S3 mini stop working (black screen .. doesn’t show anything.. and won’t turn on ) you think is it software or hardware problem ? if it is a hardware problem how i can check it?
    thank you

  9. Avatar owoso oluwaseyi says:

    Hello mr Santosh please how can i use my IMEI to track my phone either on website or any application

  10. Avatar Anand says:

    my micomax x551 not charging through adapter but separately through Battery charger but stilll not getting switched on.

  11. Avatar Anand says:

    my mobile micromax x551 feature phone is not working as once charged through charging point gets heated and also not getting switched on no led light fluctuation no display,charged by connecting the charger to multi-use charger and got it charged but still phone not getting switched on.Kidnly help

  12. Avatar Rahul says:

    Hello sir , micromax a94 charging shows but not store in battery, charging shows below 2.9 volts on batfery connector , how it will solve, i am waiting ur rply

  13. Avatar Jeevan says:

    Sir I have learnt mobile repairing an year ago through skill India. Your article helped me remembering many things.
    Thanks for sharing.

  14. Avatar Prashant Kumar says:

    Dear sir i want to Samsung E2152 power key track

  15. Avatar Kirankumar says:

    Sir these test doing with on mobile or mobile off condition on pcb..

  16. Avatar richard says:

    hello sir i read your article about identifying shorts in PCB, however am still a bit not sure. the question that i want to ask is that can one bad capacitor cause the other to bee or get bad?. reason being is that am checking my note 4 board for shorts buy while doing so i found out that when i test more than one capacitor their is a bee sound.

  17. Avatar Jose Albogado says:

    Hello sir, my Samsung J7 Pro 2017 fell off from my pants pocket to the floor while I was sitted down on work (it fell with the screen facing upwards). When it hit ground, this weird white squares appeared on the screen, but they instantly disappeared, and the screen didn’t showing anything., except for a strange red/white flash every 10 seconds or so. The phone also vibrated whenever the flashes occured (a short vibration, like the one that happens when you turn on the phone, or put it to charge). At this point, I thought that it was the screen that had broken up, but later, some loud, annoying sounds could be heard from the phone, they were like strong buzzing sounds. They eventually stopped, but came back every now and then, and only stopped completely when the phone finally ran out of battery. Could you please help me with this problem? Could the motherboard have been damaged with the fall, being that the reason of the sounds? Or are they related to the screen?

  18. Avatar Hemasurya says:

    How to find out if fault in mobile phone sir

  19. Avatar Nayan Jain says:

    Sir,my phone Gionee M5 lite switched off after the battery went 0%.I tried to charge it but ,it didn’t charge and so never turned on.I took it to a local repair shop,he told me that the ‘Power IC ” has got damaged so you’ll need to change the mother board.It’ll cost around Rs.5000!!What should I d0.

  20. Avatar Bhautik says:

    Hi sir , my Sony xperia c4 dual is showing a message ” unfortunately, system ui is not support ” and | phone is not connected through datacable to laptop or PC to diagnosed problem please give solution on how to connect phone with laptop or PC to repair it

  21. Avatar Hari says:

    Hi sir, this is harish. My Micromax canvas express 2, is getting heated very much, if I speak continuously for 10 minutes, is there any solution for this?

  22. Avatar Ceena says:

    hello sir
    i have dead Huawei p8 mobile phone, when i trying to insert a new battery or old its getting hot like burning in 3 to 10 seconds, same heating with connecting to power supply also. if connect to supply more than 10 seconds there is smell like burning.
    i jave trace the charging section is heating.
    please help sir , which part is faulty

    • Santosh Das Santosh Das says:

      Change the battery connector.

    • Avatar Ceena says:

      hello sir
      i also replace the sim connector, but still same issue.
      before charging connector replacing the consuming current (amp) is around 4.5 now around 2.4 , but heating same.
      the charging connector value is around 290. and another side no value. its look like ok.
      same value when i remove connector and check the connector point.

  23. Avatar Simon says:

    Good day Sir, how can I fix Nokia C2 displaying contact service

  24. Avatar Mohamed akidh says:

    Sir can we solve any mobile phone without fail.?

  25. Avatar Davies says:

    Sir please can have your email address so i can send you some Chinese mobile pcb board pictures that i am having problem solving the charging system so that you can show show me how to go about it. Thank you sir i like your site Alot it has made to become the best mobile repairer in my area for now thanks.

  26. Avatar Vijay says:

    Sir can you please help me?

    I have samsung cdma sch b339, the mobile is full short.

    I have go to many mobile shop but nobody repair it. So I have decided to repair by myself.

    I have seen many video on YouTube and I have checked that my phone PCB has many shorting capacitor and ragistance, so I have removed those by checking multimeter.

    Now my phone is on but phone is not showing the network tower.

    The phone is accepting the sim on starting like Tata or MTS but after starting the phone, the phone showing searching and after that phone shows that No service……..

    So can you please help me in this problem, I want to repair it…..

  27. Avatar Malik berry says:

    but sir ,i need a job i know how to repair

  28. Avatar esb 199798 says:

    Nokia c1 01 No screen &keypad light problem after water damage what is solution ?

    • Santosh Das Santosh Das says:

      Disassemble the Phone. Take out the PCB. Clean with IPA or Alcohol and allow to dry. Now Apply FLUX all over the PCB and Apply Heat from some distance using Hot Air Blower. Assemble Back and Check.

  29. Avatar mali ali says:

    Sir plz tell me how to remove half shortage…..

  30. Avatar amit says:

    How to confirm Mobile phone pcb is ok

  31. Avatar farman says:

    Sir ,How To check Handsfree Interface On Nokia 230 pcb

  32. Avatar Ritam Roy says:

    My phone touch screen is passing obstructively what to do ?

  33. Avatar AMAN KUMAR says:

    Hello sir my android mobile spice 525q is no service bta rha hai. .how to check contiti. .or kitni contiti honi chahiye. .. plc btaye…thanks

  34. Avatar UTECH says:

    help me my phone PC just stopped to power on

  35. Avatar Mayur says:

    Is it possible to repair fully shorted mobile?

  36. Avatar Shankar says:

    Hi sir mujhe mobile repair Kaise karte hai Sabh Mail me dona

  37. Avatar Anas says:

    I havr asus zenfone 5 , it has 2150 mh bettry backup , but actully it does’t work only 2 hrs , although it have to works minimum 6 hrs , but thier bettery not working good , although i changed the charger and its Data cable for fast charging and keep maximum time on bettry time duration . But still not stays for long hrs ? What should i do ?

  38. Avatar Maas Safraz Naveed Weerabangsa says:

    I just insert the dc power suppley to a samsung galaxy y phone to check but i just forgot to regulate the voltage for 3.7 and at that time the voltage was 11 so waht may be happend to that phone??

  39. Avatar Ali says:

    my mobile flash light is not working i change the led bulb but still not working and usb malfunction jab pc say connect karain gay tu message ata hai usb device is not recognize Please tell me is ko kaisay repair karain gay

  40. Avatar Ptarul says:

    my nokia 1100 ringer is not working after first step jumpering

  41. Avatar Navod Naveendra says:

    Hello Sir

    My mobile phone is draining its battery really soon.
    I replaced the battery but it didnt make much of a difference.
    I also replaced the charger and the cables.

    According to your knowledge, Do you think its Power IC fault?


    • Santosh Das Santosh Das says:

      I don’t think there is any fault in the power IC. Which Phone are you using? See if the battery is Loose or Not. Also remove unwanted Apps and make proper settings for display, wi-fi, Bluetooth etc.

  42. Avatar samuel segun sonayon says:

    i want to apply for a certificate training from you sir, if u don’t mine pls.

  43. Avatar Milan Das says:

    Hello sir, can call you ?

  44. Avatar MUDIT GUPTA says:

    Hi Santosh, I have Samsung Galaxy Note 2 4G model # SGH-I317 (AT&T model from US) which I had been using for past 5 years. Recently phone fell down and stopped responding. When connected with charger over night no progress is shown on the screen other than Samsung Galaxy Note II message. I recently got it check in open market and some said motherboard is not working, charging IC, is not working,etc. No one have this model component and telling to change with Indian component which is 3G. Now I have decided to self repair my phone. Can you guide me and help in this project to idenfy and rectify what part or component on the circuit board need to be replaced so that this carrier locked phone can become reusable. Thanks in advance.

  45. Avatar kishan says:

    Bhai mere pas ampear vala DC he mujhe power ic ya cpu karab he kese pta clega….

  46. Avatar mtata says:

    sir i find out power on/of is under voltage what to do.

  47. Avatar shaikh sayeed says:

    please let me know various problem solutions of a smart phones and the way to check it through multimeter and PCB it will be very kind of you

  48. Avatar ganesh says:

    Repair and maltimitar solution reply

  49. Avatar shaikh sayeed says:

    thanx a lot sir I am from Maharashtra Latur dist. Udgir. Generally ICS are not available so from where should we buy and LCDs and touch of good quality c/c mic speakers please suggest

  50. Avatar shaikh sayeed says:

    fine sir its great to have you may God bless you . Sir how to learn a chip level work where is your institute and how much fees .please respond .

    • Santosh Das Santosh Das says:

      I had my own institute but in West Bengal but it is closed now because I am too busy with my other projects. I don’t know your location but there are many institutes in India providing Chip Level Training. I will suggest you to visit any Samsung Service Center and talk to the person doing chip level repairing and ask for some good institute in your location.

  51. Avatar Meelan says:

    Why Nokia Mobiles short using after DC supply machine. After that mobile short only in Nokia tell me pls. Why happen

  52. Avatar wasswaz says:

    Thanks soooooooo much i like you!

  53. Avatar shajahan says:

    Hi sir How to identify power ic , network ic etc….. Pls tell me sir

  54. Avatar Muideen says:

    tecno y4 is decreasing charging, what is the solution

  55. Avatar Anakh Ajayan says:

    Really good site

  56. Avatar Right says:

    Thanks.. God bless you

  57. Avatar Danny says:

    Got a broken phone and it is probably the Power ic. Now, is it possible to take the Power ic from another used phone (same modell) or is it just a bad idea?
    I just want to make it work so I can recover pictures and stuff. So it does not have to be a “good” fix that make the phone work for a long time.

  58. Avatar Asif says:

    Sir ,

    i started learning ,mobile phone repairing ,my question is -if customer brings mobile phone which is not working and he may not knowing the exact problem what are all the things we need to check first ,can u pls. explain me with steps .

  59. Avatar Krishnamurthyk says:

    V nice brother

  60. Avatar Alan says:

    Thank you very much for all your work, Santosh. It really helps.

    Best regards from Brazil.

  61. Avatar Hashmat says:

    sms mein “r” Key kaam nahi kar raha hai

    mi a120 Hai plz help me

  62. Avatar subho ghosh says:

    Hello sir any death mobile solution please

  63. Avatar saqib says:

    How to check whether a mobile is short or not, by both analog and digital multimeter?
    And i got 2 new mobiles like a month ago but when i check them by connecting opposite colour probs to the opposite colour battery connector of them, the needle of analog multimeter moves slightly and go forward and remain there, i have read that if the needle of analog multimeter moves forward even a little, it means that the mobile is faulty and short, but both of them work fine. When i checked them through dc power supply, there was no sign of any short. So plz clarify?

  64. Avatar GHAJINI says:


  65. Avatar Mohd. Anish says:


  66. Avatar MAHER says:

    HI , Thank you for your help ! How do i know the components name ? for an example : if i have galaxy device and if i want to locate the power IC , how do locate that component ? I will waiting for your response . Thanks mate!

  67. Avatar karthikeyan says:

    1)In Multimeter which one is good digital or Analogy
    2)If digital meter first Where can i set the for check ohms

    • Avatar karthikeyan says:

      1)In Multimeter which one is good digital or Analogy
      2)If digital meter first Where can i set the for check ohms(In multimeter)
      3)If Analog meter first Where can i set the for check ohms(In multimeter)

  68. Avatar Gabal Babaji says:

    Hi sir i like ur site very much.body of my cell phone is short .how can i solve this problem.

  69. Avatar Gabal Babaji says:

    Hi sir i like ur site very much.but i have a problem,body is short how can i solve this problem

  70. Avatar thaunghtay says:

    thank you

  71. Avatar .saeed ahmed says:

    Hi sir where r u?

  72. Avatar .saeed ahmed says:

    Aoa Sir very nice l like it. Sir plz send me Iphone like 4 4s 5 5s repairing tips to my this Gmail address plz.

  73. Avatar yogendra garg says:

    Sir mujhe mobile ki pcb track check kaise krte fuse coil capcatrs digital mieter me kiase check krte hai video chahiye

  74. Avatar jitprakash says:

    jai bigyana…

  75. Avatar raheem says:

    Sir how to check series current in tablet

  76. Avatar YORDANOS says:


  77. Avatar rahul says:

    this is a great site,

  78. Avatar H.Murugan (mtrendz) says:

    iam not a technician but i visit this this web page. Now i would like to achive a tech..
    very very thanks to all.this articles very usefull…….

  79. Avatar amit says:

    Hi samsung v3303 no network problem

  80. Avatar Murphy martins says:

    My blackberry turch1 phone is draining fast the battery., pls what’s your advice.?

  81. Avatar amit says:

    My nokia c1 is dead on/off swicht voltag 1.43v how to solv

  82. Avatar manoj goyal says:

    Can u explain the cool testing,hot testing,parallel track and series track

  83. Avatar Fred says:

    Hi, Great site. My Samsung Galaxy Y. switches on but will not get past opening flash and SAMSUNG letters will not go beyond this and when I press off/on with operation key it just goes back to same. Any ideas.

  84. Avatar kamal says:

    Iphone 3g heating problem near power control ic, check the capacitor as said beeps ?, battery charging connector on logicboard shows 0.7 v on charger plugged , charging port Ok .pls help

  85. Avatar amit says:

    How to solv problem

  86. Avatar amit says:

    Tellme. How solv the problem

  87. Avatar amit says:

    Yes i reset the phone and other sim check but not ok

  88. Avatar amit says:

    My nokia mobile problem
    “Invalid sim” how to problem solv

  89. Avatar Sayyed Ismail says:

    Hello thanks for detail this is very help full for me

  90. Avatar sanjay says:

    Cant hear callers voice in mobile earpiece ,but can hear in loud speaker what is the problem and how to rectify

  91. Avatar Suresh says:


    I have Karbon a21 the power on mother board is OK but no display. I changed the display but still it is blank and the display is getting hot at the bottom. What to do now?

    • Santosh Das says:

      There is some short in the phone. The phone Karbon A21 has faults in its design and manufacturing. This is a common problem in all A21. It is better to get rid of the phone and buy a new one. Any money you spend on its repairing will be waste. Never trust Karbon.

  92. Avatar A karthik Srinivas says:

    Very useful tutorials… Thanks a lot…

  93. Avatar Roki says:

    My mobile phone is turning off. when headphone jack through 9v dc supply.whats the problem.
    thank !!!

  94. Avatar raj says:

    is ur collage in jalandhar punjab state thanks

  95. Avatar Sushil Kumar says:

    good site.I like.


  96. Avatar safwan says:

    hi ray,

    is there any institute of urs where i can learn mobile repairing course


  97. Avatar James Imaga says:

    Hi,I’m highly impressed by your tutorials they’re are top class and easy to understand and moreso highly factual I want to say its one of the best I’ve come across on mobile phone repairing tech.Keep the good work up.Please can you send me some tutorials on mobile phone jumper setting I’ll be very grateful.Thanks.U can use my email to reach me.

  98. Avatar Eyayu says:

    Very very thanks it is great knowledge in this site .

  99. Avatar yemane says:

    you done it best thanks!!

  100. Avatar Raju Jat says:

    I love This site

  101. Avatar modou says:

    this offers useful guide to beginners in cellphone repair.we would be glad if the info is more comprehensive. thanks a lot

  102. Avatar sanyog salve says:

    Hi sir
    I like this site and i learnt so many things .
    and i m very great full to you.

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