Repair Guide: How to Check Your Phone for a Short Circuit with a Multimeter?

  The multimeter can not only be used to measure the AC and DC voltage, current resistance, but also can be used to judge whether the smartphone is short-circuited, so how to do it? Next, let's learn how to use DT-17N multimeter to check whether a mobile phone is shorted.

  How to check for half short circuit?

• Leave the DMM in beeper mode.
• Check the positive phone battery connector (red lead to positive, black lead to negative). If the value is 1 on the multimeter, the PCB is fine and there are no shorts.
• If the value is 25 in Forward Checking, there is a Half Short.
• Now check the reverse battery connector (red probe on negative and black probe on negative). If the value on the multimeter is between 350 and 650, there are no shorts and the PCB is fine.
• If the reverse check value is 350, there is a semi-short position.
• A Half Short exists if the values in the forward and reverse checks are the same.

  How to check for a dead short?

1. If there is a BEEP sound on both forward and reverse checks, there is a Full Short.
2. If we connect the positive ( + ) and negative ( - ) terminals of the battery connector to a DC power machine, and the amp starts dropping without turning on the phone, then the phone's PCB is dead shorted.

  Solutions to Fix Short Circuits in Phones

  First, to fix the half-short, the first step is to disassemble the phone and clean the PCB thoroughly with an IPA solution, then use the ATTEN ST-862D Hot Air Gun Soldering Station to heat the entire board.

  Assemble the phone back and check if the problem is resolved.

  In most cases, the problem is resolved. But if there is still a half short, then check for tiny SMD capacitors near the battery connector. Remove the faulty one.

  Next, connect the positive ( + ) and negative ( - ) terminals of the battery connector to the DC power machine with a dead short. The amp will start dropping without turning on the phone.

  This means that there is a dead short in the phone's PCB. Faulty components can become hot. You can feel the heat of the failing component with your fingers. This component needs to be replaced.

According to the above description, you can use a multimeter to check and repair the short circuit fault of the mobile phone. If you need the above maintenance basis, welcome to our Phonefix website.