Checking the refrigerator capacitor with a multimeter: a complete guide with photos and diagrams

The capacitor in the refrigerator is a small but critical part that is responsible for starting the compressor. When it fails, the unit stops freezing, makes strange sounds, or refuses to turn on at all. At the same time, externally the capacitor may look absolutely intact: without swelling, cracks or signs of burning. The only reliable diagnostic method is checking with a multimeter.

In this article you will find step-by-step instructions with photoshow to correctly ring a capacitor, decipher the instrument readings and understand whether replacement is needed. We will figure out what types of capacitors are used in refrigerators Atlant, Indesit, Samsung and other brands, and also learn to distinguish a starting capacitor from a working one. No theory - only practical advice for home repairs.

Why the capacitor fails and how it manifests itself

The capacitor in the refrigerator works in tandem with a compressor and a start relay. Its main task is to accumulate and release electrical charge in order to create the necessary torque to start the motor. Over time, the part wears out due to:

• 🔥 Voltage drops on the network - a common reason for regions with unstable power supply.
• ⏳ Natural aging - electrolytic capacitors lose capacity after 5-7 years of operation.
• 🌡️ Overheating - if the refrigerator is located next to the stove or in an unventilated room.
• ⚡ Short circuits in the compressor or relay circuit.

How to understand that the problem is in capacitor? Here are the key symptoms:

• 🔊 Compressor buzzes, but does not start —you can hear it trying to turn on, but after 2-3 seconds it turns off.
• ❄️ Refrigerator doesn’t freeze, although the light inside is on and the fan is working.
• 💥 When turned on, it sounds relay click, but the motor does not start.
• 🔄 Refrigerator turns on every other time —it works normally, then it “rests” for 10–15 minutes.

⚠️ Attention: If the capacitor is swollen or electrolyte leaks from it, it is needed replace immediately without waiting for a test with a multimeter. Such a part can cause a short circuit or even a fire.

What tools will be needed for testing

To ring the capacitor yourself, prepare:

• 🔧 Multimeter (digital or analog) with a capacitance measurement mode (20 µF–200 µF).
• ⚡ Screwdriver with an insulated handle - to discharge the capacitor.
• 🔌 Pliers or wire cutters - to disconnect the wires (if the capacitor is not removable).
• 📸 Smartphone —to photograph the connection diagram before disassembling.

If you do not have a multimeter with a capacitance measurement function (Cx), you can get by resistance mode (2000k Ω). However, this method is less accurate and is only suitable for rough diagnostics.

⚠️ Attention: Do not use bare wires or a screwdriver without insulation to discharge the capacitor. The voltage in the circuit can reach 300–400 V, which is dangerous. life.

Preparation for testing: safety precautions and disassembly

Before touching the capacitor, it is necessary dischargeEven. if the refrigerator is unplugged, the part may store a dangerous charge. Follow the instructions:

1. Unplug the refrigerator.
2. Remove the back cover (or panel where the compressor is located).
3. Locate the capacitor - usually it is black or a silver cylinder with two terminals attached to a compressor or relay.
4. Short the terminals of the capacitor with an insulated screwdriver (or a 20 kOhm resistor) for 5-10 seconds.

Now you can begin dismantling:

• 📷 Take a photo of the connection diagram - this will help not to confuse the wires during reassembly.
• 🔌 Disconnect the wires from the capacitor (you can mark them with a marker: C — common, F — fan, H — hermetic).
• 🔧 Unscrew the mount (if the capacitor is fixed on the frame).

If the capacitor is soldered into the board (relevant for modern models LG or Samsung with electronic control), you will need to solder it for this. For this you will need a soldering iron with a power of 40–60 W and solder.

Step-by-step instructions: how to ring a capacitor with a multimeter

There are two testing methods: capacitance measurement (the most accurate) and check for open/short circuit (if the multimeter does not support Cx). Let's look at both options.

Method 1: Measurement capacitance (mode Cx)

This method is suitable for digital multimeters with a capacitance measurement function. Procedure:

1. Set the multimeter switch to mode Cx (usually designated as 20 µF or 200 µF).
2. Connect the probes to the terminals of the capacitor, observing the polarity (if the capacitor is polar, then + k +, − k −).
3. Wait for stable readings on the screen.

Compare the obtained value with the nominal capacity indicated on the capacitor body. Permissible deviation - ±10%. For example, if it is written on the capacitor 35 µF, the actual value should be in the range 31.5–38.5 µF.

Method 2: Checking resistance (mode 2000k Ω)

If your multimeter does not support capacitance measurement, you can test the capacitor in resistance mode. This method is less accurate, but will help identify obvious faults:

1. Set the switch to mode 2000k Ω (2 MOhm).
2. Connect the probes to the capacitor terminals.
3. Observe the readings:
   • At first the resistance will be low (due to the charge of the capacitor).
   • After a few seconds it should increase to OL (infinity).

Swap the probes - the process should repeat.

If resistance remains 0 (short circuit) or immediately shows OL (break), the capacitor is faulty.

How to distinguish a starting capacitor from a working one

Two types of capacitors are used in refrigerators:

• 🔋 Starting —helps the compressor start, connected through a starting relay. Usually has a capacity 80–120 µF.
• 🔄 Working - supports the operation of the motor, is constantly connected. Capacity 15–45 µF.

In most models (for example, Atlant MHM 1705 or Indesit BIAA 13) it is used one combined capacitor with two terminals: C (general), F (for fan), H (for compressor). In this case:

• The capacitance between C and H is a starting capacitor. data-i="202">The capacitance between
• Capacity between C and F is a working capacitor.

In refrigerators with a system No Frost (for example, Samsung RB-30 J3200) there may be a separate capacitor for the fan. Its capacity usually does not exceed 5 µF.

How to find a capacitor in an electronically controlled refrigerator?

In modern models (for example, LG GA-B489), the capacitor can be hidden under a plastic cover next to the compressor or even on the control board. If you do not find it outside, check:

• 🔍 Under the bottom panel (at the back of the refrigerator).
• 🔌 In the block with a relay and a starter.
• 📱 On the main board (if the refrigerator has a display).

In this case, to check, you will have to unsolder the capacitor or use special probes to measure “on-site.”

What to do if the capacitor is faulty: repair or replacement

If the check showed that the capacitor is faulty, you have two options:

• 🔧 Replace it yourself — suitable for those who are confident users.
• 👨‍🔧 Call a technician - if you have no experience working with electricity.

To replace you will need an analog capacitor with the same parameters:

• Capacitance (µF) - must match the original (deviation is ±5%).
• Voltage - not lower than that of the old capacitor (for example, if there was 450 V, the new one should be 450 V or 500 V).
• Type - electrolytic (for starting) or film (for working).

Where to buy a new capacitor:

• 🛒 In stores of spare parts for household appliances (specify the model of the refrigerator).
• 🌍 On AliExpress or eBay - search by parameters (for example, 35 µF 450V).
• 🔧 In radio stores - if you know the exact characteristics.

⚠️ Attention: Do not install a capacitor with a lower voltage than the original. For example, if there was a capacitor in the refrigerator at 450 V, and you set it to 400 V, it will quickly fail or even explode.

Frequent errors when testing and how to avoid them

Even experienced technicians sometimes make mistakes when diagnosing capacitors. Here are the most common ones:

• ⚡ Do not. the capacitor was discharged before testing - this can damage the multimeter or cause an electric shock.
• 🔄 The polarity was reversed when connecting the probes - electrolytic capacitors are sensitive to this.
• 📏 The temperature was not taken into account - the capacitance of the capacitor changes when heated or cooled.
• 🔍 We checked only the starting capacitor, forgetting about the working one (or vice versa).

How to avoid mistakes:

• Always discharge capacitor before measurements.
• Use crocodile clips for reliable contact of the probes.
• Check the capacitor at room temperature (20–25°C).
• If the capacitor is swelled or leaked liquid, do not waste time checking - change it immediately.

FAQ: Answers to frequently asked questions

Is it possible to check the capacitor without desoldering it? circuit?

Yes, but only if it is not connected to other elements of the circuit. In the refrigerator, the capacitor is usually connected to the compressor and the relay, so for an accurate check it needs to be disconnected. An exception is if you measure the resistance in the 2000k Ω mode and see an obvious break (OL) or a short. short circuit (0).

Which capacitor is better: electrolytic or film?

Usually used for refrigerators electrolytic capacitors (they are cheaper and more compact). Film capacitors are more expensive, but more durable and less sensitive to temperature changes. If you are replacing a capacitor, take the same type as the original.

What will happen if you install a capacitor with a larger capacity?

If the capacity exceeds the original by 10-20%, nothing bad will happen - the compressor will start a little longer. But if the difference is larger (for example, instead of 35 µF set 100 µF, this can lead to overheating of the compressor windings and its failure.

How to check the capacitor in a refrigerator with an inverter compressor?

Inverter refrigerators (for example, Samsung RB-37 J5240) use a different operating principle, and they are often installed non-polar capacitors. They are checked in the same way as conventional ones, but it is important to consider:

• The rated voltage is usually higher - 500–630 V.
• The capacity may be less - 10–20 µF.
• The circuit may have several capacitors (for power factor correction).

If you are not sure, refer to the circuit in the instructions for the refrigerator.

Is it possible to restore the old capacitor?

Theoretically, you can try to “reanimate” the electrolytic capacitor by training. data-i="295">replace it with a new one (gradually applying voltage), but this is a temporary solution. In 90% of cases, the restored capacitor will last no more than a month. It is much more reliable and safer replace it with a new one.