How to Test a TV Power Supply with Multimeter (6 Easy Steps)

The power supplies in electronics are of significant importance. Because they are the primary electric device used to power an electric load. The primary function of a power supply is controlling the power delivery to an electric or electronic device.

It receives the electric current from a source and delivers only the required amount of voltage, current, and frequency to the device, ensuring that it works properly and does not misbehave.

Power supplies can be externally connected to machines, but some devices incorporate internal power supplies, such as a desktop computer.

Here’s How to Test a TV Power Supply in Easy Steps:

A multimeter is the easiest manual method that is used to test a power supply. Overheating and high currents are the most known reason for causing the failure of power supplies.

Therefore, it is always a good idea to test your power supply with a digital multimeter. Following are the essential steps for testing your power supply using a multimeter.

Step 1:

First of all, ensure your safety before trying to diagnose a power supply. For this purpose, use safety gloves as insulation to avoid any mishap with electricity, like a shock.

Step 2:

Plug the power supply into an outlet

Step 3:

Now turn on your multimeter and adjust the settings to set to read the DC Voltage.

Step 4:

Note the voltage rating written at the power supply.

Step 5:

Take the red probe of the multimeter and connect it to the end plug of the power supply. While holding the connection between the red probe and the plug, pick up the black probe and connect it to its barrel.

Tip: Make sure not to touch the probes with each other as it can cause a short circuit.

Step 6:

Note the reading on the multimeter screen; if it is just a volt above the given rating, the power supply is OK. For example, a 12V power supply can show a 12.55 volt in the multimeter.

TV Power Supply Symptoms

If the voltage reading is shallow, half a volt or less than the given rating, there is a problem with the power supply. If the multimeter shows a negative reading like -12.56 volts, then your probes are connected in reverse.

If your TV turns off unexpectedly or gives start-up warnings, then there is a possibility that the power supply of the TV is not working correctly. Using a multimeter can be of great help in such a situation.

  • The power supply should just be plugged in, and the cords of the multimeter should be connected to the power supply pin.
  • The voltages should be compared to the ratings of the power supply.
  • For a power supply to be functioning correctly, the voltages must be within the range provided in the power rating.
  • If it is not the case, then the power supply is defective, and the TV must not be used with such a power supply; it needs necessary repairs before it can be of further use.
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Test a Computer Power Supply with a Multimeter

Expensive devices such as desktop computers which are expected to cause a heavy loss in case of inappropriate power delivery are given particular importance in pairing them with the proper power supply and mostly come with a built-in power supply.

  • After turning the power supply on, the negative probe should be connected to the ground, and the positive probe should be connected to the pin to be tested.
  • The process should be repeated for all of the pins and voltages must be compared with a given voltage range.
  • If voltages are not in range, the PSU is probably defective.

Test a Power Adapter with a Multimeter

A power adapter can also be tested with the help of a multimeter. The process of testing the power adapter using a multimeter is straightforward.

  • Just plug In the power adapter into an outlet.
  • Put the pin of the red probe into the tip while the pin of the black probe touches the outside of the barrel.
  • Compare the reading on the multimeter screen to that of the power rating given on the power adapter.
  • The power adapter is working fine if the multimeter shows an adequate number compared to the power rating. Otherwise, it has a problem.
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