Mobile Phone Capacitor Ultimate Guide

If you want to check the polarized capacitor on a mobile phone's PCB, this tutorial is for you. All methods for finding and checking capacitors in mobile phones are the same. You can use both digital and analog multimeters to check capacitors on smartphone motherboards. But first, let me tell you what a capacitor is.


A capacitor stores electric energy as an electric field between conductive plates separated by an insulating dielectric. When a voltage is applied, charges accumulate, creating potential energy. Capacitors are important in electronics; they store energy and shape signals.

Phone capacitor

Types of Capacitor

There are different types of capacitors are made for specific uses based on factors such as capacitance, voltage, size, and tolerance:
  1. Ceramic Capacitor
  2. Electrolytic Capacitor
  3. Film Capacitor
  4. Supercapacitor
  5. Variable Capacitor
  6. Silver Mica Capacitor
  7. Tantalum Capacitor
Types of Capacitor
7 Capacitors
  • Ceramic capacitors are widely used for their small size, stability, and suitability for high-frequency applications.
  • Electrolytic capacitors are capacitors that use an electrolyte to achieve a higher capacitance value. They are often used in power supply circuits and other applications that require larger capacitance values. 
  • Film capacitors are made from insulating plastic film, have a wide range of capacitance values, and, due to their highly reliable and stable, they are ideal for various applications.
  • Supercapacitors also known as ultracapacitors or electric double-layer capacitors (EDLCs), supercapacitors can store a large amount of energy compared to traditional capacitors and can be quickly charged and discharged. 
  • Variable Capacitors have adjustable capacitance values. Typically are used in tuning circuits and applications requiring variable capacitance
  • Silver Mica Capacitors insulation is made of mica. This thing is really solid and accurate for capacitance values. They are commonly used in Precision applications.

The Tantalum Polarized Capacitor

Tantalum polar capacitors are used in the latest smartphone circuits. Tantalum Polarized Capacitors are typically used in large-voltage mobile phone situations, such as Direct Current line filtering to reduce noise related to uneven DC voltage levels. Mainly value is measured in microfarads. Polarity is critical to mobile devices

Note: Check Polar Capacitor with a Digital multimeter on Buzzer Mode. If it is good, then the Digital multimeter will NOT give any beep or Buzz sound. If there is a buzzer sound on the Digital multimeter from both +VE and -VE sides then the polar capacitor is faulty. Replace it with a new one.

Why Polarized Capacitor Short Lead

Polar capacitors can have internally shorted terminals, excessive leakage, and degradation of the capacitance meter. Short the terminal capacitor to discharge it prior to testing.

Capacitor Polarity

Certain types of capacitors have positive (+) and negative (-) terminals, which are known as capacitor polarity. For proper operation and to prevent damage, polarized capacitors must be connected in a specific polarity, unlike non-polarized capacitors, which can be connected in any orientation. Electrolytic capacitors and tantalum capacitors are particularly sensitive to their polarity. Polarized capacitors include aluminum electrolytic capacitors and tantalum capacitors.

capacitor polarity
Polarized capacitors

Due to the nature of their internal construction, they are designed to operate in a specific orientation. A thin insulating layer forms between the plates of these capacitors. Dielectric layers allow capacitors to have higher capacitance values, but they also make capacitors polarity-sensitive.

Capacitor Value

The capacitance of a capacitor, measured in farads (F), is its ability to store charge per unit voltage. In electronics, capacitors commonly come in fractions or multiples of a farad, such as microfarads (μF), nanofarads (nF), and picofarads (pF).

SMD capacitor value
Measure SMD capacitor

Online calculators are available to convert capacitor values between different units, including pF, nF, μF, and F. Users can input a value in one unit and receive the corresponding value in another unit.

Click here and check out an online capacitor value conversion calculator that can help you convert capacitor values.

SMD Capacitor (Surface Mount Device)

SMD onto the surface of a PCB. They are used in modern electronics due to their small size, ease of automation, and suitability for high-density circuit designs. They come in various types, including ceramic, tantalum, and electrolytic, each with specific characteristics for different applications.

SMD capacitors
Mobile phone SMD capacitor

SMD capacitors, which lack leads, are soldered directly onto PCB pads. Their small size is ideal for compact electronic devices like mobile phones, laptops, and automotive electronics.

How to check SMD capacitor value using digital multimeter

capacitor checking
How to measure SMD capacitor

Using an XC6013L digital multimeter, you can check the value of an SMD (Surface Mount Device) capacitor as follows 5 steps:

  1. Select the capacitance mode on your digital multimeter by selecting the symbol that looks like the capital letter "F" or the word "Cap" on the dial.
  2. Select the capacitance measurement mode on your digital multimeter by selecting the symbol that looks like the capital letter "F" or the word "Cap" on the dial.
  3. Connect the multimeter leads to the terminals of the SMD capacitor. Polarity is irrelevant for capacitors so you can connect the leads in any direction.
  4. Ensure that the digital multimeter displays the capacitance value of the SMD capacitor in appropriate units, including scientific notation if necessary.
  5. When measuring capacitance, compare it to the expected value provided by color codes, markings, or circuit documentation.

Keep in mind that capacitance measurement mode is not available on every digital multimeter, or their accuracy in this mode may be limited. So, measuring capacitors still soldered in a circuit is not accurate due to the influence of other components.

Xc6013L manual

Best capacitance meter

The XC6013L is a capacitance meter particularly used for measuring capacitors. This device is designed to provide accurate readings of capacitance values in various units such as microfarads (µF) and picofarads (pF). The meter offers a wide measurement range, spanning from 0.1 picofarads to 20000 microfarads. It operates on battery power and has low power consumption.

And at the end of this blog post some useful free resources to learn about smartphone repairing

13 Ways to Learn smartphone repairing course Step by Step from investing less money to Getting Practical Training Visit Smartphone Repairing Tutorial 2023 for more details

I am sure the information on this mobile phone capacitor blog post helps you understand how to check capacitor polarity with the multimeter and apply it to your mobile phone PCB.

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