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How to check repair mobile short circuit board fast

18 Jan 2014
All Phone Short finding method is same.you can use Digital, Analog Multimeter, and Digital Power Supply both to find the shortage in smartphone motherboards.

You also can use a DC Digital power supply for testing Shortage but this is better to find where or which part of the smartphone is really short. This way is not a good way to identify a shortage because DC Power supply can't detect very small shorts in the motherboard which cause some faults on Phones. So remember the best method is using a Digital or Analog Multimeter.

How To Find if a Phone Circuit Short or Not using Digital DC Power Supply

Put power to your Smartphone using DC Power Supply(As your Phone's DC power needs) Normally 3.8 volts is enough and in tablets, 4 volts some Chinese mobiles needs 4.2 volts 

Connect Power Supply Red clip to Battery Connector +Vbat pin 
And connect Black clip to both Battery Connector BSI and GND Do not touch any volume or power button

If your Digital or Analog Power supply's Ampare Reading Scale shows any of current amount that’s mean there is a shortage in it.
If your Power supply Shows “0.00” on Ampare Reading Scale it means there is No any shortage in motherboard


The Very easy and quick method to find if there any shortage on a Phone is using Analog Multimeter. 

Put multimeter to x1 buzzer or x10
Check Battery Connector two pins

simply put (+) test meter probe on GND pin and (-) test meter probe on +Vbat Pin

if the Analog multimeter pointer moves even a little there or buzzer is short.


Short circuit Checking method with Digital Multimeter.

Set multi-meter on CONTINUITY
Scenior1: Connect Black probe to Circuit's +VE print.  and Red probe to Circuit's -VE print shows some reading.
Scenior2: Connect Black probe to Circuit's -VE print and Red probe to Circuit's +VE print shows no reading.
Note: IF reading shows in BOTH scenarios it means circuit has Shortage.

How To Remove Shorting In Smartphones Motherboard

If your smartphone is short, it can have various issues like it may not turn on (dead), it may overheat (although it is normal in some smartphone models!), its battery may drain and discharge very fast, it may hang or auto restart and freeze frequently, it may auto turn off sometimes, etc. It is called short-circuit smartphone motherboard.Before removing shortage you should know whether your smartphone motherboard is short or not.

Reasons for Shorting in Smartphone Motherboard How Does a Phone Get short?

If the smartphone gets dropped on the floor or on some hard surface.or the phone gets wet or is dropped in rain or swimming pool water.
phone overheating.
Trying to use the faulty charger for charging in the smartphone.
Electric Sparks or smoke coming out of the Phone due to any reason form Handset charging port.

To repair a short smartphone, you will have to first remove its shortage to repair it. You have to follow the procedure to remove it, especially in dead Smartphones.

Procedure To Remove Shortage In Smartphones

1. disassemble your Smartphone and get out the printed circuit board (PCB). Be careful, so that you do not damage it! I suggest you watch the disassembling video on youtube first then remove LCD, camera, etc because we just need the motherboard.

2. Clean the entire motherboard thoroughly with any circuit cleaner like Philips contact cleaner spray, alcohol, thinner etc. Now dry it completely. After each cleaning step, you have to check if the shortage is not gone proceed to the next step.

3. Now try to deep clean the Phone Circuit Board. There is a liquid called Elma used by smartphone repair technicians in the Eastern Europe countries named Elma.

Elma procedure: Dip the Circuit Board in Elma for 1 to 2 hours. Remove the Circuit Board and clean it thoroughly with a toothbrush. Dry the Circuit Board completely with cotton or ultrasonic cleaner machine, not even a droplet of water remains. For drying, you can use direct sunlight or 100-watt yellow bulb.

this article link. To know where we can get a particular free pdf notes and service manual guides to repair phones from all manufacturers mobile phone brands Find Relevant Information here


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