# Troubleshooting

## MULTI-Module LEDs

LEDs are present on most external MULTI-Modules and can be used to check the status of the module.

The basic functions of the LEDs are:

**Green LED** - indicates that the MULTI-Module is receiving power\
**Red LED** - indicates the status of the MULTI-Module

{% hint style="warning" %}
On TMX5 modules the red LED patterns are reversed.  (Also note that TMX5 modules are [not officially supported.](https://www.multi-module.org/basics/module-hardware/unsupported-modules))
{% endhint %}

| Red LED State     | Pattern                                        | Meaning                                                                                      |
| ----------------- | ---------------------------------------------- | -------------------------------------------------------------------------------------------- |
| Off               | Off                                            | The module is not functioning.                                                               |
| Flashing          | On 0.05s; Off 1s                               | The selected protocol is not available on the module.                                        |
| Inverted Flashing | On 1s; Off 0.1s                                | Waiting for bind to be initiated.                                                            |
| Fast Blink        | On 0.1s; Off 0.1s                              | Binding in progress.                                                                         |
| Slow Blink        | On 0.5s; Off 0.5s                              | Module is in Serial Mode but there is no signal from the radio.                              |
| Very Slow Blink   | On 1s; Off 1s                                  | Module is in PPM Mode but there is no signal from the radio.                                 |
| Fast Double Blink | <p>On 0.1s; Off 0.1s;<br>On 0.1s; Off 0.5s</p> | Serial debugging is waiting for a serial connection.                                         |
| On                | On                                             | The module is operating (transmitting).                                                      |
| SOS               | Three short; three long; three short           | The firmware has detected that it is running on an MCU with less than 128KB of flash memory. |

## Module Status

OpenTX and EdgeTX will display the state of the MULTI-Module in the **Module Status** line of the RF module section on the **Model Setup** page.

### Normal Operation

In normal operation the Module Status will display the MULTI-Module firmware version and the Expected Channel Order.

![Module Status with Firmware Version and Channel Order](https://3357080223-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LwnWq9OVxVlVodwNBnH%2F-Lxjt_boavfqWBbrmVvH%2F-LxjwliC9eqUtWpR1L14%2Fch_order_aetr.png?alt=media\&token=a636b8d3-ec12-442a-9961-8865b4408db5)

If an auto-binding protocol is selected, and binding has not yet been initiated, the Module Status will display "Bind to load protocol".

![Module Status waiting for Bind](https://3357080223-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LwnWq9OVxVlVodwNBnH%2F-Ly6E1INFgAnN4_CVGfS%2F-Ly8GxwQ5o6jik26zj_E%2Fbind_to_load.png?alt=media\&token=d9783cdc-ebc0-4b9c-b89e-685118d82471)

When the module is binding, the Module Status will display the firmware version followed by "Binding".

![Module Status Binding](https://3357080223-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LwnWq9OVxVlVodwNBnH%2F-Ly6E1INFgAnN4_CVGfS%2F-Ly8HjRjvg2yW8xtiuDv%2Fbinding.png?alt=media\&token=262634b5-a377-4068-b92a-63d3019f769f)

### No MULTI Telemetry

{% hint style="warning" %}
If the Module Status displays "No MULTI\_TELEMETRY" or "No telemetry" there is a problem with the MULTI-Module
{% endhint %}

![Module Status No MULTI Telemetry](https://3357080223-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LwnWq9OVxVlVodwNBnH%2F-Ly5srDNorYBqk8BajJ1%2F-Ly69HGor2SflBJDWAI_%2Ffrsky_tx.png?alt=media\&token=45f13437-e13a-4f06-87b1-554b5bac05df)

In this situation, one of the following may be the cause:

* The selected module is not installed - External is selected when Internal should be, or vice-versa
* The wrong firmware is installed on the module - the wrong radio firmware, or telemetry inversion setting was used
* The module is defective
  * A somewhat common fault is bad solder joints on the 5-pin module bay connector

## **Getting Help**

There are two ways to get help:

**RC Groups Forum** - for general 'how-to' questions or advice from other users\
**GitHub Issues** - for reporting bugs or serious issues

{% hint style="info" %}
RC Groups is usually the best place to start as the forum is very active, with many experienced users who can provide help and answer questions.
{% endhint %}

To make it easier to provide help, please include the following information:

* MULTI-Module type and the firmware version
* Radio type, firmware, and firmware version
* Using PPM or Serial
* Description of what the LED on the MULTI-Module and the receiver/model are doing
* Explanation of the behaviour and reproduction steps