How to solve the most common Compex problems?

To charge your Compex muscle stimulator correctly, make sure the battery is properly inserted into the device and connect the charging cable to the first channel.

The charging connector is protected by a sliding red cover. If it appears to be covering the connector, don't worry: it is not broken. It is part of the original Compex design and is intended to protect the connector when it is not in use.

To connect the charger, follow these steps:

• Make sure the battery is properly inserted into the device.
• Slide the red cover to the right to expose the charging connector.
• Connect the charging cable to the first channel of the Compex.
• Allow the device to complete the charging process.

During charging, the other channels will remain locked. This is completely normal and is part of the device's normal operation while it is connected to the charger.

In the following video, you can see how to charge your Compex muscle stimulator correctly:

How to charge a Compex muscle stimulator correctly?

During the first few charging cycles of your Compex muscle stimulator, it is normal for the battery level indicator to be less than completely accurate. The system needs some time to adjust and properly calibrate the charge indicator.

As the device does not have fast charging, the first few charging cycles may take more than 10 hours. This does not necessarily mean there is a problem with the battery or the muscle stimulator.

We recommend following these guidelines:

• Fully charge the device.
• During the first few charges, keep in mind that the process may take several hours.
• After approximately 12 hours of charging, you can disconnect the device normally.
• When you turn it on, the device may indicate that the battery is fully charged.

After that, you can use your Compex normally. As the device goes through different charge and discharge cycles, the battery becomes calibrated and charging times stabilise, gradually becoming shorter.

If the CHECK message is the only thing that appears on the screen when you turn on your Compex muscle stimulator, the most common cause is that the battery is completely discharged.

This can happen especially when the device has been unused for several months and the battery has been left inside the device during that time.

In this case, we recommend following these steps:

• Fully charge the battery.
• Once charging is complete, disconnect the charger.
• Turn the Compex muscle stimulator on again.
• Check whether the CHECK message has disappeared.

In most cases, the device will return to normal operation after a full charge.

If the CHECK message continues to appear after charging the battery, the battery may have lost capacity over time and may need to be checked.

If your Compex muscle stimulator does not recognise one of the wireless modules, the module may have become disconnected from the device.

To pair it again correctly, follow these steps:

• Turn off the module that the Compex does not recognise.
• Turn it on and hold down the on/off button for approximately 15 seconds until it switches off completely.
• From the Compex main menu, go to Settings.
• Select “Pair a new module”.
• Turn on the module you want to synchronise again.
• Wait a few seconds while the device searches for the module.
• The Compex should recognise it and indicate that it has been successfully paired.

In the following video, you can see how to correctly pair the Compex modules:

How to synchronise Compex modules step by step

If your Compex turns on correctly and the screen works normally, but you do not feel any muscle stimulation, the issue is likely related to the positioning of the electrodes.

In many cases, this happens when double electrodes are used without the correct polarity, which can prevent the muscle stimulator from transmitting the stimulation signal correctly.

To check this, try using two small individual electrodes. When used correctly, the device should deliver current normally.

In the following link, you can find information on how to position the electrodes correctly:

Electrode placement for muscle stimulators (EMS) | Compex

If the screen on your Compex muscle stimulator appears too dark or is not displayed correctly, you can adjust the contrast directly on the device.

To do this, press and hold the power button until the settings menu appears. From this menu, you can adjust various system settings, such as the language and other options.

Go to the screen contrast option, which corresponds to the second channel in the menu, and adjust the level to your preference.

Once you have configured it, turn off the device to save the changes. The setting will be saved automatically on the muscle stimulator.

To ensure effective and comfortable stimulation during every session, it is important to take proper care of your Compex electrodes. Their condition directly affects the quality of stimulation and how well they adhere to the skin.

Although Compex electrodes have an approximate lifespan of 30 uses, proper care can help them last even longer.

To extend their lifespan, we recommend following these tips:

• Always apply them using the “ON” side of the protective plastic they come with.
• Apply them to clean, dry skin, avoiding creams or oils that could reduce their adhesion.
• Store them in the refrigerator after each use, as the cold helps keep the adhesive gel in better condition and extends their lifespan.