Gerber 408 Y-Encoder/Motor Error on Start Up

[cubanitaloka]

Hey all. I'm at the point of ripping my hair out figuring out what's wrong with this Gerber Sabre 408 CNC. Below is everything I've done so far.

Issue: On startup, the error "Y Encoder/Motor" appears on the panel.

Attempt #1:
- Cleaned and oiled gantry rails
- Checked lead screw - it moves well manually
- Checked X and Y cable connections, pins, sockets - everything looks good
- Checked front and rear limit switches. They looked ok.
- Swapped front/rear limit cable with right/limit cable
- Error switched to "X encoder/motor"
- Purchased new front/rear limit cable
- Installed new cable
- Y encoder/motor error continues

Attempt #2:
- Check X/Z limit switches, replace with new switches just in case - Y encoder/Motor error
- Swapped X Encoder, Motor and limit cable connections with the Y - error switches over to the X
- Disconnected Y servo motor and plugged in directly to electrical box - Y encoder/Motor error
- Removed and swapped servo boards for the X and Y on the side of the electrical box - Y encoder/Motor error
- Based on the manual troubleshooting steps it appeared we needed a new Y motor so we ordered it
- Received and connected new Y motor directly to electrical box - panel finally loads to "A: Orient"
- Installed motor directly underneath lead screw and connected to longer encoder/motor cables
- Begin orientation, within 2 seconds of it moving - Y encoder/Motor error
- Swapped X encoder/motor cable connections on the electrical box - error changes to "X encoder/motor error"
- There is nothing else to change except the longer Y encoder/motor cables

Attempt #3:
- Receive new Y encoder/motor cables and connect to new Y motor - Y encoder/Motor error
- Swapped X encoder/motor cable connections on the electrical box again - panel loads to "A: Orient"
- Returned encoder/motor to correct position - Y encoder/Motor error
- Swapped servo boards again - Y encoder/Motor error

At this point I have brand new Y encoder/motor cables, front/rear limit cable and a new Y motor. I shouldn't be getting a Y error. If it was one of the servo boards I'm assuming the error would change to "X encoder/motor" but it doesn't. Currently when I swap the X encoder/motor cable connections with the Y I get "Arient" and loads up just fine.

Any advice would be greatly appreciated

 

[cubanitaloka]

Attempt 4:
- Swapped x encoder/motor cable connections with Y - Y encoder/Motor error
- Swapped the front/limit and left/right cable connectors as well - Y encoder/Motor error
- Returned all cables to their correct connections, inverted the ribbon connectors for the X and Y on the top side of the electric box image attached - Y encoder/Motor error

 

[Vassago]

Have you checked the encoder?

Sometimes they can get loose or have a poor electrical connection.

 

[Vassago]

Encoders usually have an index mark, perhaps when you wiggle things it does something strange so it wants to orientate it - then doesn't give the right signals

 

[cubanitaloka]

Have you checked the encoder?

Sometimes they can get loose or have a poor electrical connection.

Which encoder are you referring to? The cable that connects to the electrical box or the ribbon cable on top of the main circuit board?

 

[JBurton]

I thought the encoder was built into the motor?
How about the connection on that board... if you squeeze the cover over the ribbon cable as you boot, does it help?
Does reconnecting the Y motor to the board, unmounted, with a shorter cable cause it to work?
Can you 'choke up' on the ribbon cable? Slice off the cut areas where the pin blades go through the ribbon and reinstall it.

 

[cubanitaloka]

I thought the encoder was built into the motor?
How about the connection on that board... if you squeeze the cover over the ribbon cable as you boot, does it help?
Does reconnecting the Y motor to the board, unmounted, with a shorter cable cause it to work?
Can you 'choke up' on the ribbon cable? Slice off the cut areas where the pin blades go through the ribbon and reinstall it.

Finally figured it out. There's two small cables (red and black) that connect to the main motor cable connection on the old Y-motor. The black cable had a small tear and was not making proper connection. As a result the motor was not getting power. I repaired the cable, tested the motor and worked perfectly. I then tested the old Y motor & encoder cables and those also worked as well.

There was also a pin on the X motor long cable that would retract a bit when connected; I believe this was causing an issue as well.

The previous tech had left all cables tied together with a lot of constant tension, I believe over time this tension caused all of these problems.

Thanks for everyone that chimed in.

 

[JBurton]

Finally figured it out. There's two small cables (red and black) that connect to the main motor cable connection on the old Y-motor. The black cable had a small tear and was not making proper connection. As a result the motor was not getting power. I repaired the cable, tested the motor and worked perfectly. I then tested the old Y motor & encoder cables and those also worked as well.

There was also a pin on the X motor long cable that would retract a bit when connected; I believe this was causing an issue as well.

The previous tech had left all cables tied together with a lot of constant tension, I believe over time this tension caused all of these problems.

Thanks for everyone that chimed in.

Hell yeah! Good write up throughout the whole process, hopefully this will help plenty of folks later on, double props for actually following up after tracking down the solution!