How to Diagnose Mobile Phone Problem – Diagnostic Codes

Learn How to Diagnose Common Mobile Phone Problems with Secret Diagnostic Codes

Here we Learn How to Diagnose Mobile Phone Problems with Diagnostic Codes. Learn How to Diagnose Common Mobile Phone Problems with Secret Diagnostic Codes.

How to Diagnose Mobile Phone Problem – Diagnostic Codes

What are Secret Diagnostic Codes to Test & Check Phone Hardware Condition

Diagnostic codes, also called, secret codes, help to get a closer look at the inner functionality of a phone. Most mobile phone repairing technicians use these diagnostic codes to troubleshoot Feature Mobile Phones, Android Smartphone. and Apple iPhone.

You may remember that whenever you go to a technician or any service center, the first thing they do is enter some code with # symbol and some numbers and few other symbols. These are nothing but Diagnostic Codes that help the technician to know about the exact problem. They have a list of such codes and they use them as and when required.

There are a list of these diagnostic codes for Android phones, iPhone, China phones and other phones. Most manufacturers provide such list with their manual that comes with a new phone.

Below you will find a list of Codes to Diagnose Mobile Phone Hardware Problem. Make sure to use them with caution. Read carefully what each diagnostic code does before entering them in your phone. Some codes can wipe OFF the firmware or delete the vendor-specific updates from the OS. So, be extra careful.

How to Diagnose Mobile Phone Problem

There could be times when you may need to troubleshoot / diagnose your mobile phone or Android Smartphone when there are problems such as Slow Performance, Audio Problems, Touchscreen or Display Problems or any other such Hardware or Software Problem.

There are in-built Diagnostic Tools and Downloadable Apps that can help you easily and quickly diagnose your mobile cell phone and troubleshoot and fix the problem.

Mobile Phone Secret Diagnostic Codes

  • iPhone – 3001#12345# * – This will display “Field Test” on your iPhone where you can easily test each part of the phone’s functions.
  • BlackBerry: TEST
  • HTC: *#*#3423#*#*
  • LG: 2945#*# or 2945*#01*#
  • Motorola: ##7764726
  • Nokia: ##3282
  • Samsung: * #0011#
  • Sony: 904059+>

The above codes will help you identify software or hardware problem and then it becomes easier to find the solution. Please note that the above codes may not work on all models.

Video: Best Free App to Test Android Mobile Phone Hardware – Check Touchscreen, Display, Sensor, Mic

List of Useful Secret Codes for Android Mobile Phones

Code

Function

*#*#0*#*#*

LCD Test

*#*#0673#*#*
OR
*#*#0289#*#*

Melody Test

*#*#0283#*#*

Packet Loop Back

*#*#0842#*#*

Vibrator and Back light Test

*#*#2663#*#*

Touch Screen Version

*#*#2664#*#*

Touch Screen Test

*#*#0588#*#*

Proximity Sensor Test

*#*#3264#*#*

RAM Version

How to Diagnose Mobile Phone FAQs

To access mobile phone diagnostic codes, open the phone app on your device, and enter the code "#0#" on the dial pad. This will bring up a menu of options, including diagnostic tests for various parts of the phone, such as the display, sensors, and cameras.

Mobile phone diagnostic codes provide information about the health and status of various components of the phone. The codes can indicate issues with the phone's battery, camera, touch screen, speaker, and more. Each code corresponds to a specific test or diagnostic function.

Mobile phone diagnostic codes are not intended to fix problems with the device but rather to diagnose them. Once you have identified the problem using the diagnostic codes, you can then take steps to fix the issue, such as resetting the phone or seeking professional repair services.

If you don't understand the mobile phone diagnostic codes or are unsure how to interpret them, you can consult the phone's user manual or contact the manufacturer's customer support for assistance. Additionally, many online forums and communities offer support and advice for troubleshooting mobile phone issues.

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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, Keep visiting for daily dose of Tips and Tutorials.

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85 Responses

  1. Akash Krishnatrya says:

    Sir it’s great work by you in the first place.my Moto g5(splus) shows no network at certain place and sometimes catches network and data..sometimes call doesn’t work but internet works.when running the cqaa test I got sim iccid null and phone iccid unknown.please help me identify the problem

  2. Kapil says:

    Samsung m30s Hang and reboot issues.
    This is coming in all m30s users. How can we fix this?
    I have downgraded android 11 to 10 using odin and it was successful but still hang-reboot problem exists.

    Is it mothboard issue? Or software ?

  3. Abbie says:

    Not able to change network, all choices except 2g only are greyed out. I should be able to change it, but can’t.

    Please help, if you can.

    Thank you.

  4. Shannon Stubbs says:

    Sir,
    I have a Nokia 3.1c, and before now, it was two other times when then battery went down to 1%, and stayed for a long time. The charging cable was replaced, and it didn’t do it again for a long time. The next time it happened it took a long time before we could ever get it to power back on. What’s actually happening according to research, is the phone shows it’s charging with the charging cable disconnected. I’ve cleaned the port, and checked to see if it was loose. It wasn’t, but I know that after I cleaned the port, the phone charged, and worked like it was supposed to for about twenty four hours. Can you help me? It’s no longer under warranty.

  5. Techieds says:

    Thanks for this

  6. Johnny Torres says:

    Can a spyware phone hacking thru wifi or just by sending it be traced back to who sent it to my phone? And I need my metro phone to have a diagnostic test do i take it to them? Thank you sir

  7. Jayachandra Buduru says:

    Refaralcode Samsung j2

  8. RABIU says:

    hello sir, my iPhone 5c grows vertical lines with different shapes on the screen. please sir what is the solution. Thanks

  9. Andrew says:

    Well, this is very interesting. You took time to answer all questions. It is a good place one can come and enhance learning.

  10. Dammy says:

    hello sir, i changed my tecno K7 screen and the phone since then my phone fails to receive reception indoor unless i go outside. Please what couls be the problem

  11. jimmy simwaba says:

    Sir, i have a problem with my Sam sung phone .

    the problem is that it is not showing any icon on the screen it is just black but am able to receive calls . what is the solution.please help.

  12. Wale says:

    Hi, where can someone buy your phone repair equipment tools. Also, can you let me know how to contact you or where to your office address is located in India. Thanks and have a nice day.

  13. VICTOR says:

    MY PHONE JUST PRESS ITSELF WHAT CAN I DO?

  14. sudha says:

    hi,

    I am using Nokia – 2 4G LTE with 8GB Memory mobile, unfortunately dropped into water, and tried to remove the battery but heared some vibration sound couple of times, then i was not able to remove battery, then dried in rice bag for 48 hours, but its not working, its not charging also, could you please give me solution for this.

    • You have to disassemble the phone completely and clean the PCB with IPA or Alcohol or Petrol and then apply Liquid Flux and give some hot air. this will solve all problems.

  15. Ver says:

    How can I bypass the Google account for Tecno N2?

  16. Toufik06000 says:

    I have a BlackBerry curve 9380 who’s become apparently dead, it can neither turn on nor accept flash (haven’t tried with a box)
    The symptoms are as follow: when you connect it to the charger, a charging icon appears after a while the phone tries to load Os but turns off. I noticed that it heats a little after connecting to a charger for some time.

  17. Ben says:

    I have a cracked s7 edge screen. My phone’s screen wasn’t working, only the LED lights and blue light at the top of the samsung phone were working. I figured i should wait until the phone’s battery drained, then charge it and it should work. This worked, but the phone restarted and froze multiple times when it was fully charged- alas it still worked and so did the screen. However, while i started to use the phone it completely shutdown on me. This time it’s just a black screen. I have been to repair shops and they are telling me the battery is functioning fine, it’s either the screen or motherboard. WHAT SHALL I DO?

  18. Manish malviya says:

    Sir my phone full charge battery down in 2hours what is the problam in my lenovo k4 note

  19. sudheer sachan says:

    dear sir i have use mi5 mobile. this mobile screen light on randomly without any reason. but this problem not show when mobile charge.
    please give me solution.

  20. zain says:

    sir i have a iphone and i put your secret code that you mentioned above in my iphone then nothing happened so tell me how to check through the code please

  21. Jaivik says:

    Sir i have hcl me g1 tab whenever i try to run something even of 60 mb it strt to misbehave and freeze as it is until the btry dies and have to chrg it again to on what can i do

    • Reset the Tab and check. If the problem is not solved then you cannot do much. Sell it off and Buy a Better one. Never Trust LG as far as Smartphone and Tab is concerned.

  22. Tariku says:

    my phone screen becomes dark when dialing(out going call)

  23. Sir I have removed the battery and check the pcb board still cant power on the tab it a china tab

  24. RAJAN KUMAR says:

    sir i have moto E 2nd generation . he he automatically shutdown few months ago then he will not ON again.
    please help me

  25. sehgal says:

    sir i have videocon a15 its touch automaticaly select the options . what is a problem.

  26. uche emeka says:

    plz Mr Santosh i need your whatsapp contact so u can enlighten me on more solutions….i really need your help….

    • Pls mr santosh I had a tab that cant power on again after charging trying using dc to check still dnt connect

      • There could be some fault with he Batter Connector. Remove the battery, if possible and clean the 3 copper connectors and check. If the battery cannot be removed then disassemble the tab and clean the connectors.

  27. Jyoti ranjan sahoo says:

    Dear sir,i am a user of BQ s 40.One day all of a sudden error messege “Unfortunatly,the process.com.process.acore.has stoped flashes,then differenr simillar messeges continiously appears.when I attempted to Factory reset/wipe data,it was not work.I attemted it several times. then I had tried to clean eMMC. It also not working .And still that probleme exists.Please mention the solution.android kitkat 4.4.2 verson.Now I am not able to Change my pattern lock also,

    • Take the phone to a service center and ask then to reinstall the software. This is a software issue and can easily be fixed @ Rs. 100/- to 150/-

  28. satyam mohanty says:

    my samsung galaxy core 2 display is work properly.it”s sometime automatic operate, iam very irited, pls give your usuful opinion for reparing.

  29. emmanuel ben says:

    please sir. I am a young youth an i will like to be a phone repairing wizard in my area. I don’t no how i can communicating with sir. Please sir i do need to learn more. Thanks

  30. Mushrif says:

    Hello Sir,
    I have galaxy s4 GT-I9500. Airtel 4g sim is not working most of the time being said that once in a while it works and after sometime it will give the message no sim..Is there any way to correct this..jio sim is working fine in my phone..
    Thank you

  31. Eldhose baby says:

    Hi santhosh,

    My name is Eldhose. on regarding of my iphone 6. i heard a noise from inside of my phone. and i opened the phone and release the screen and put it back . but my touch is not working at the moment.

    thank you
    Eldhose

  32. mishyck says:

    i am one of the youth interested in phone repairing. I think this website will help me most to achieve what i wanted.

  33. Mary says:

    Hello sir. How can I use this codes? Is there a specific app I should download? And if yes I download it to the device I want to check or in any android device. Thank you in advance.

  34. Mark Flores says:

    Thank you ive learn a lot from you..my plan today is to go school for cellphone repair course.i accepting repairbut not all i repaired.very hard for me.i hope i can learn more and more soon in your website.thank you More Power and God bless

  35. Mohamed says:

    Thats Great , Thank you for YOUR hard effort

  36. Nirmal says:

    Hi bro. I have a UBISLATE TAB .Its touch screen is not working. Suggest me some idea

  37. Steven says:

    Very interesting information on phone repair. As a retired electronics technician I try to keep up with changes in electronics technology. Your site looks like what I want to learn more about, phone repair.

  38. Dibyaprusty says:

    Sir,
    My phone battery is draining very fast and charging very fast,,,and some times my phone automatically switch off and on many times…..plz suggest some thing….myphone model===intex cloud n12

    • Geoffrey says:

      Good article put together to assist those like me wishing to know more on phone repairs. What a kind gesture. Thanks and God bless you.

  39. Nwodo Chidi Paul says:

    I am a phone technician, there is this phone, Gicent T545, I tried to use rework to fix the simcard connector mistakely a lot component near it fell off. I cannot fix it because I don’t know the arrangement. I have been searching google to see the PCB Diagram (Gicent T545). Please help me!

  40. Tintong Borang says:

    am an unemployed youth and I do beleive that your tutorials will help unemployed youths to earn their livelihood through repairing works.Lots and lots of thanks Santosh Bhai.

  41. Nawaz says:

    I like to learn cell phones service.your articals tutorials are very usefull.we expect your online support.thank you

  42. Manish Yadav says:

    Sir
    I have a Lava IRIS 501 mobile. When i call to anyone or receive a call form my mobile ,the display of the mobile just off so icannot be able to do anything in my phone, but when the call just disconnected the display of the mobile works normally. Please help me

  43. irshad says:

    huawei diagnostic wich code number

  44. vishwas says:

    Mobile model-Karboon A101
    My prob is when mo off then it only switch on charging bye laptop or PC…when charge 1% then mo on…after that no charge by any other charger

  45. Umesh Band says:

    I have a lenovo p780. It recognises the sims but has no network on both the sims. An ‘x’ mark is displayed. I cannot use the phone, Can you help

    • Please try to insert another SIM or another Network and check. If the problem is still there then clean the SIM Slot with Alcohol and allow the Alcohol to evaporate. Insert the SIM again and check. Also see if there is Network problem in your area. If everything is OK and there is still no Network then there is Hardware problem with the Network IC. The IC Needs to be replaced at Authorized Service Center.

  46. Sonia says:

    Hi. I have no problem donating to you, but I would like to see some of these codes actually work first. How do I input them

  47. sanjay says:

    I have Samsung mobile duse 2
    Problame in sim 1 not working so m 2woring proper
    I have formet cell phone but sim 1 not working .sim 1hide plz some solution

    • Please go through the SIM Management Option and change the required settings.

      • Vijay Shinde says:

        Hi Santosh Ji,
        I am using Samsung Galaxy S4 LTE. its around 26 month old phone and has suddenly started showing me No Sim Card, Emergency Calls Error. I have tried changing Sim Card Slot but It dint work out. We are unable to find out exact reason of this error. how to do troubleshoot and find out the problem

  48. Bidyut Kumar says:

    My mobile that is a problems any time power on of

  49. abel says:

    TIA for ur free information keep going.

  50. E.Raghu says:

    I have useful

  51. ANIL says:

    Its amazingly detailed information on this website about repair of mobile phones. Thanks

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