Welcome to our mobile repairing course hardware Class. in this class we cover the following four topics.
- what is continuity mode on a digital meter and how to use beep testing to check Ground Line on Phone PCB
- Check Shorting on Phone Battery Connector
- Check primary line VBAT battery voltage positive
- What Do You Do When a Smartphone Won't Turn On
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mobile jumper diagram |
when we are checking a wire and we want to check whether the wire is broken or not form inside in the phone PCB we use beep testing.
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continuity test with multimeter |
- One is called Primary line
- Two is called secondary line
Multimeter Continuity Mode
in phone PCB checking with multimeter continuity mode is extremely beneficial in verifying primary and secondary line breaks using a multimeter
Continuity test with multimeter example:
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continuity multimeter symbol |
as you can see in the picture below verify connections from one path to another path
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how to check continuity in a long wire |
if you hear a beep sound its means wire is ok
The wire on phone PCB called tracks. to check primary and secondary track lines we use continuity mode on a digital meter.
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multimeter continuity mode |
Mobile Jumper Solution
in every mobile PCB, there is a battery connector. if you know it you know a mobile jumper solution. it has three tips one is called primary line VBAT battery voltage positive. 2nd is called secondary line ground or GND means negative and 3rd is called Battery Status Indicator or BSI. in Phone PCB ground is the baseline
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battery connector jumper |
Ground Continuity Test with Multimeter
mobile repairing students know in mobile repairing course hardware Ground Continuity Test with Multimeter is the first lesson on the Mobile Jumper topic. As we know power comes with a VBAT, GND, and BSI line in mobile PCB with mobile battery, Secondary Ground Line on mobile PCB is signified by the yellow strip that you see all across the phone PCB. first of all, we will check the Ground Line in Phone PCB. to check it is connected to battery connector set your digital multimeter on continuity buzzer.
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pcb grounding techniques |
then place one probe on connector GND and touch another probe on that yellow strip if you hear a beep sound its means it is minus.
PCB Grounding Techniques
do you have a question how to check mobile components are connected to grounding line in phone PCB grounding techniques? this updated information helps you. to check which print is ground apply the same technique we use this method to check whether two points are connected or not to check which component leg is connected to ground apply the same method. if you hear buzzer sound and its show 0 reading its means it is minus.
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Mobile components |
you can also use this technique To check primary line VBAT.
from one point to the other easily and in those cases, we use jumper setting to try and connect those two points directly thereby ensuring the correct transmission of power, data, and piles voltage from one end to the other end but in order to determine whether you need to do jumper setting.
Do you want to download this mobile jumper solution pdf guide right now?
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mobile jumper solution |
you can read it when it’s convenient for you. Get A Free PDF Document Of This jumper wire uses in mobile phone repairing Best way to get complete information on Mobile jumper solution pdf guide 2020
Now if you are the beginner mobile repair student read this blog post untell end to take complete advantage of this mobile repairing course hardware class. the blog post covers the following topics.
- Check Shorting on Phone Battery Connector
- Check primary line VBAT battery voltage positive
- What Do You Do When a Smartphone Won't Turn On
Tracing & Testing VCC main and GND points of a iPhone PCB
Step 1 Check Shorting on Phone Battery Connector
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positive negative bsi |
Step 2 Checking Phone PCB Ground Resistance with Multimeter
you need to identify the positive and the negative points on a battery and we already know that the negative point on the battery is what is the background connection as you see the yellow color line is the GND line of the battery that is traveling all through the mobile PCB so let's keep the probes on one end and connected and now we can hear the beep this basically means that the battery connector negative point is here. if two GND points are connected you will hear the beep sound if not you will not be able to hear a beep sound in these points by segmenting the entire negative line into smaller parts you will be able to exactly trace where the breakages in the entire negative line once the breakage is identified you will then need to use the jumper setting option and try and ensure that the wire is or the circuit is reconnected and is properly functioning![]() |
ground testing |
Positive Line VBB or VCC Main in iPhone PCB
now this is how we check the negative line now let's move on to the next part which is a positive line now a positive line cannot be very clearly seen like the negative line the positive line is typically connected to very specific components or ICS and supplies power to each of those components so it's not very easy to identify and it's not open unlike the negative line hence you need to ensure that you are able to trace the positive line effectively after reading through the circuit diagram of the respective iPhone PCB
Mobile Jumper Solution Circuit Diagram Download
unless you have an iPhone Circuit Diagram in hand you may not exactly know how the positive ways is weaved it into the iPhone PCB or into the specific components of the Printed Circuit Broad so please ensure that you pick up their respective surface circuit diagram of the while phone that you are working on understand the VCC main connections that exist in it and then try and trace the connections
now one of the common things that we can do to check the positive ways is to touch the positive terminal +VBAT of the battery connector to this layup capacitor now this component is a very common component that you will find in most phone PCBs and this is a commonplace where the positive ways is usually connected you may be able to identify that in different phone PCBs
Step 3 Checking Primary line VBAT battery voltage positive
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back point is connected to the power point |
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power supply system in phone |
if you want to learn testing or tracing the negative and positive ways faults in iPhone, Samsung PCBs take admission in smartphones problem and their solutions course
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pcb diagram of mobile phone |
if your phone keypad not working? then read this information on Quick and Easy Keypad Fix For Most Cell Phones
What Do You Do When a Smartphone Won't Turn On?
in a smartphone, this is a common issue. to fix this in smartphone try to long press the Power Button. in many cases, the power button won’t work because the phone is basically frozen or Historically, the solution is to remove the battery, wait for 10 seconds, then reinsert the phone battery and press the power button again. This removes all the power internally form the smartphone circuit. first, try this to fix the problem. just hold down the power button for ten seconds. If this method doesn’t work, try to press the power button for a bit longer. ten seconds should be suitable for most smartphones, Many smartphones have a method to restart usually by holding down specific keys or buttons on the phone. Much like the Sony Experia and Motorola battery pull where you hold the volume down key and power key simultaneously while the mobile is powered off. Try using a laptop or car charger instead can put a quick charge on phone battery and get it to respond as well. If you have tried these methods and the phone isn’t responsive due to its battery drained 100% Try charging it using a battery booster(12 volts DC adopter with Ampare) this device is used to boost mobile phone batteries if you don't know how to use this device to fix the dead phone batteries read digital multimeter step by step guide article DC Current Measuring topic.![]() |
phone turn on vibrate |
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stuck on logo samsung |
Hold Volume Up + Volume Down + Power.
Hold Volume Down + Home + Power.
Hold Home + Power.
If none of these button combinations work, try performing a Google search by typing an android phone name and hard reset keys to find the correct key combination of customer device. for example
(Samsung s3 hard reset keys)
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android boot recovery mode |
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samsung factory reset code |
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performing hard reset |
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hard reset screen |
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refuses to switch on normally |
To perform a factory reset on your smartphone form recovery mode visit hardreset.info to know your phone recovery mode buttons
then performing a Google search by typing the android phone name and service manual to find the phone schematic diagram. then check VBAT and GND both Power Supply in smartphone PCB with the help of the schematic diagram.
I think to learn about mobile repairing jumper and how do we do the jumper settings on phone PCBs one article is not enough for you to understand the process for identifying where the circuit is broken in the negative and positive line of a mobile PCB in Dead, Not Charging, Battery Consumption, Auto-Off, water Damaged, Fallen Damaged, NO Vibration, No Tones, No Network, No Ear speaker Voice, No Mic Voice, LCD Disappear faults.
I will tell you those faults step by step jumper setting, all mobile jumper setting free download in my next article so keep visiting my blog, I hope you would have understood how to test a positive and negative power supply in your phone PCB and we hope that you will continue to keep learning more about how to repair phone prints
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