How to Repair Cell Phone?

Every second there are phones get damaged!

Our phones are easily to get drop damaged, water damaged or just stopped working without a sign.

Let’s see how to repair cell phone briefly.

First of all, ASK!

Ask the client how the phone get damaged? For different situations, the repair processes are different.

• For water damaged phones, we need to dry the cell phone with heating platform and disassemble the whole cell phone to cleaning the motherboard.

• For drop damaged phones, we should focus on checking the cosmetic of parts and motherboard to see if there is any flex cable damage, parts damage, components missing, etc.

• For the phones which just suddenly died or with function abnormal issue, it might be caused by parts like screen, charging port, battery etc. which can be fixed easily. Or it might be the CPU or inner rail broken issue which is hard to repair…

Secondly, part replacement

Based on the defect phenomenon, we can first try to replace the related parts to have a try.

And here must mention again, do more practice to ensure you can disassemble the phone without causing new damages. Then we can try to replace the parts like screen, battery, charging dock, camera, etc. to have a try.

Thirdly, if the issue still unresolved. Then check the motherboard

First check the cosmetic of motherboard under microscope carefully

• For some issue like water or drop damage, we maybe can find out the defect easily.
• Some small components missing, mouldy, corrosive. Let’s deal with them first!

After that, if the issue still unresolved, then let’s do the diode value measurement.

• For diode value measurement, you just need a multimeter, and a bitmap software for diode value reference
• By measuring diode values, if we find any pin with abnormal diode value then just track the rail related components. To find it out and replace it with a new one.

• Tips, above diode value measurement seems simple, but also with many details need you to pay attention. For example, when measure diode value on connector, do not press too hard to avoid deform the connector pins. 

After the diode value measurement finished, if still not fix the issue. Then we’ll need to apply the power to measure the voltage values.

• we can measure the voltage and refer to a good motherboard values, to see if related chips or components with problem
• Or we can use thermal image to find out the abnormal components. 

When we find out the defect compnent, then it’s advised to replace the abnormal component with a new one.

the defect component should be replaced with the one with same specification

Or for some situation, for example filter type capacitor shorted, we can just tick it off. 

After above operation, in most cases. Issue should get resolved.

But if still can not solve the issue. Especially like no start-up, no component , no display, etc. Then we may need to reball/replace the PMU, or even need to do the most risky surgery, the CPU reballing. 

Above is just a brief introduction about the basic repair process, some tools, methods, and operation processes are not described in detail. You may visit Académie REWA to learn the detailed repair knowledge and skills.

And repair requires more practice, as the saying goes, practice makes perfect. Also it requires patience and confidence. Trust yourself and try to repair more phones, one day you’ll definitely become a repair expert.