How to check the interference filter on a washing machine

How to check the interference filter on a washing machine

The need to check the interference filter on the washing machine arises when there are problems turning on the latter. This is a capacitor, a semiconductor part that is installed on the power cord and provides current to the unit. If the equipment does not respond to a plug inserted into the socket, then it’s time to test the FPS. All that remains is to figure out how to notice and fix the problem.

Let's first find the element.

Most often, the machine does not turn on due to a burnt-out capacitor, but this guess can only be confirmed after checking the FPS. To diagnose the surge protector, you need to remove it from the washing machine. It's easy to get to:

  • Disconnect the equipment from the power supply by unplugging the cord from the outlet,
  • Shut off the water supply to the machine,
  • Remove the top cover by unscrewing the corresponding bolts on the rear panel,
  • We look under the cover and look for the interference filter (this is a small black or white round part located on the power cord).

To dismantle the capacitor, just use a screwdriver and loosen the bolts holding it. However, it is not always possible to detect a faulty part by eye; it is safer to check with a multimeter. We'll tell you how to do this below.

Let's start testing

Diagnosis of the filter begins with a visual inspection of the part and the connected wires. In 98% of cases, it is not difficult to notice signs of a fire: this is indicated by melted insulation, dark spots, a burning smell and charred contacts. If everything around the FPS is clear, you need to move on to testing.

It’s easy to check the noise filter yourself:

  • Take a multimeter and turn it on to the “Buzzer” mode,
  • We attach the probes of the device to the contacts of the capacitor,
  • We evaluate the resistance at the input and output (if there is no voltage at the output, it means the FPS has burned out).

Replacing a burnt filter with a new one is simple: just fix the “box” in its seat with a couple of bolts. The only difficulty arises in selecting an analogue - it must be purchased separately. It’s better not to try to look for a replacement part by the serial number of the machine or power. It is much faster and more reliable to completely dismantle the old FPS, bring it to the store and ask them to pick up a similar capacitor. In this case, the probability of error is close to zero.

Afterwards everything is simple: we place the filter in its old place, fix it, return the top cover and connect the equipment to the communications. We immediately evaluate the result and turn on the washing machine. If the panel lights up without problems, everything is done correctly.

How does the element function?

It is not difficult to check and replace the interference filter, but it is better to avoid damaging it. Without eliminating the cause, the new capacitor will burn out almost immediately and will have to be repaired again. The best prevention would be to understand the mechanism of operation of the FPS, assess the risks and the likelihood of a recurrence of the failure.

The filter burns out due to power surges. The fact is that an ideal power grid does not exist, and in Russia and the CIS, current surges occur very often. Every year, tens of thousands of electrical appliances and household appliances “burn”, and washing machines are no exception. With the latter, the situation is complicated by sensitive electronic modules, which permanently fail even with the slightest failure.

The noise suppression filter was created to eliminate current surges. Its purpose is to smooth out power surges, taking the brunt of the impact. But if the FPS can cope with slight “unrest”, then it cannot deal with major interruptions. If there is a sharp rise or fall in the FPS, it cannot stand it and burns out, immediately shutting down the system.

The capacitor cannot be repaired - only replaced with a functioning analogue. But installing a new FPS will not solve the problem. If your electrical network frequently fluctuates voltage, you should consider adding a powerful stabilizer to the circuit.