Pins 18-23 are dead on maestro 24ch

hi guys,
i have 2 maestro 24ch in which pins 18-23 stoped working - without any clear reason.
im very carefull with wiring etc. and its very strange that it happened 2nd time,
maybe hardware problem?
anyway to check it?


What do you mean by “stopped working”?

What were you doing just before the pins stopped working?

There is a trace on the bottom of the Maestro 24 circuit board that can be cut in order to separate the power rail of channels 18-23 from the power rail for the other channels. If that trace were cut, that would prevent any servos attached to those pins from moving. Could you look carefully at the boards and see if there is any sign of damage? Posting some clear pictures here would help.


hi again
i cant recall anything unusual before the pins 18-23 stopped working, but its hard to know when exactly that happened…
i couldnt find any damage on the board itself but i did some deeper checkings,
here is what i find:
when i checked the connectivity on the S, +, - pins 18-23 i found that:

  • there is no connectivity between the pins V and Gnd to the main power,
  • the signal pins shows connectivity between them, and shows connectivity to the main Gnd of the maestro
  • the Gnd pins are disconnected one from the other,
  • the + pins is ok - shows connectivity between them.

the check up show the same result on 2 deferent maestros.
any idea?

What do you mean when you say the pins “stopped working”? What is the expected behavior and what is the actual behavior?

There are no pins on the Maestro labeled “V”. What do you mean when you say “there is no connectivity between the pins V and Gnd to the main power”?


hi david
for servos 18 - 23 there is 3 lines of pins -
signal line, gnd line and the + line in the midlle.
at the moment, servos dont work on chanells 18 - 23.
when i check connectivity with a multymeter, i find that in this chanells 18-23, there is connection between the signal pins (which shouldnt be), there is a connection between all the + midlle pins (which should be), and no connection between the Gnd pins (where it should be).
there is no connection between the + midlle pins and any other +Vin pins on the maestro, same with the Gnd.
connection apear between the signal pins and the Gnd pin of the maestro.

the same simptoms apear in 2 maestro 24ch that i use, both suffer the same problems.
hope im clear.

There are actually 5 rows of pins for channels 18-23, and I’m worried this may be causing confusion. Starting at the edge of the board, the rows are:

  1. GND, with thick traces for returning the current from servos
  2. +, also known as VSRV, with a thick traces for delivering current to servos
  3. S (signal)
  4. +5V (out)
  5. GND

You should connect your servos to rows 1-3, the the three rows of pins closest to the edge of the board.

The measurements you made with your multimeter make me think that you might be confusing GND with S. There should be a connection between all the GND pins and there should NOT be a connection between any of the signal pins. Please double check your connections. Posting a photo here showing how the servo is plugged in would also help a lot.

By “servos dont work” I’ll assume you mean that the servos don’t move at all, even when you were expecting them to move. Do servos still work on channels 0-17 of the Maestro?


hi David,
i follow the connection the way you explained, you was right!
the confusion was, that i connect signal to the Gnd, because of the channel number that is writen near it.
now its all working and im very happy and thankful!

i realy apreciate your patient and attention!