Disco 4220 Issues Won't start

[supradupafast]

Evening all.
New to this Forum, but have always found what I needed by searching and fixing small Disco issues.
This time, i'm not so lucky.
One of my Discos won't do anymore cleaning.
I have a good battery (works in my other two discos).

When I put the charged battery, the Power / Spot / Clean / Max button light up Green as they should, but when I press any of the cleaning buttons, I just get a "EH" sound. Nothing else.. No beep, no code.. Just that annoying "EH"...
This thing is Clean, and the robot that has the least hours on. Never had this issue with the other two.

Any Ideas ? I've taken it apart, cleaned it, and still...
Thanks

[vic7767]

Your Disco is complaining that a sensor is off normal. To identify what sensor is complaining all one must do is run the built in tests.

[mfortuna]

This is normally a cliff sensor issue but as vic7767 mentioned run the diags.

[supradupafast]

Thanks guys.
After the test, appears that the right cliff sensor is not working... I've traced the wiring back to see if any damage, and opened the sensor and made sure it's all clean...
I guess I can try and get another one and see if it works.
Thanks

[supradupafast]

So the two wires to the IR have 0 Voltage (Clear one)
The other two (black bulb-like) have 4V
So, i'm assuming the problem goes back to the PCB ...
I'm new at this, so any input would help.


UPDATE..
I'm a NERD.. lol
Since the "sender IR" from the right isn't working, I've put the "receiver / Reader" and Tapped a hole in one of the middle sensor tricking the robot to think its sensor is working. All this said, I've got myself a working robot Minus the right Cliff sensor

[mfortuna]

That is a clever fix.

The LEDs are wired in series so I think you may have a shorted out LED.

[supradupafast]

It's been working fine.. the fact that it's in reality missing the far right cliff sensor, it hasn't affected its performance and still backs up when finding the stairs. Cheap (Free) fix.