Chain three 140s

[daniel.avasilichioaei]

I have finally got my hands on a 3rd 140 Pro amp and am trying the setup you suggested.  I have the 1st Master (Treble) connected to the 2nd Master (Mid) connected to the 3rd Master (Bass).  This is how they are connected: 
Amp 1 Digital 1 --> Amp 2 Digital 2 
Amp 2 Digital 1 --> Amp 3 Digital 2

The connection between Amp 1 and Amp 2 is working ok, but Amp 3 is not picking up any input into Digital 2 (it displays as orange on the display).

Do you have any idea what I have wrong.  Is it something to do with the Chainir settings perhaps?

The configurations on Amp 2 and 3 should be identical, except for the filters.
Just for debugging, you can temporarily try these three tests:

• Put the same configuration file on Amp 3 that you use on Amp 2 and see if it works. This checks that the cables are connected correctly.
  
• Swap the SD card between Amp 2 and Amp 3. This checks the configuration file used on Amp 3.
  
• Put Amp 3 in place of Amp 2 with the SD card from Amp 2. This checks that Amp 3 is not malfunctioning.
  

You can do these tests without having the speakers plugged in. If you leave them plugged in, then make sure to use a very low volume.