LED that is located between the SIM card and the USB connector.

To save battery life, the device LED flashes only at specific events. In READY mode after successful pairing, you can see LED blinking only when connected with app via Bluetooth. After device disconnects from the app, LED flashes twice. 

In Alarm mode when alarm starts, you may see random LED flashes while device registers to GSM network or communicates with server.

How to understand by just looking at LED if device works at all and whether it is paired or not ?  

  • Try to remove batteries from Monimoto, wait for at least 3 minutes and put them back in. 
    It is required in order to discharge the capacitors and to restart the device. Observe the LED from the moment batteries are inserted - if you see one long ~2 seconds flash followed by several (up to 10) short flashes, and later you see two short flashes every 2 seconds, that means device is registered on GSM and is trying to communicate with the server. In a minute or two, LED goes off.
    It means is that the device is paired to some kind of phone and batteries have power to communicate. If you missed the LED flashes and want to see them again, remove batteries for another 3 minutes and repeat the process.
  • When you insert batteries and see only one long flash ~2seconds followed by 4 short flashes and then nothing. 
    It means that device is in the default mode and awaiting for pairing.

Weak continuous light can mean 2 things:
1. Boot mode in progress 

2. Firmware was deleted and new one was not successfully uploaded. 
You can find more information about LED flashes in the manual.