There are 5 LED's on the front of the DSL-502T.

 

 

 

Not much to say about the Power LED.  If the power is connected it should be lit.

 

The Status LED will start flashing as the unit boots and once the boot process is complete it will continue flashing at a slower rate (approximately once per second) as a "heartbeat".

 

The third (ADSL) LED does nothing.  Unfortunately it is not connected to a GPIO pin so we can't do anything useful with it.

 

The fourth Ethernet/Network LED has three states:

Off = Only during the initial stages of boot.

Flashing = Could not get an IP address on the network.  Check your network connection and that you have a DHCP server somewhere that will allocate an address.

On = Network running and IP address correctly assigned.

Off = Only during the initial stages of boot.

Flashing = Could not find a configuration file for this unit at http://www.qsl.net/zl1vkaprs/dsl502t.  The configuration files are named with the Ethernet MAC Address of the unit.

On = Configuration file loaded and aprsd running.