Sudden lost of Y2 slave control

You might try measuring at the 7I76U with the plugs removed
though 4.12V sounds OK under load. (its really marginal with no load however)

I can post a program a bit later today that will toggle all the step/dir outputs
slowly for a more complete test.

Here is a little test program that slowly toggles all step/dir outputs so both states of all outputs
can be checked with a voltmeter:

 

You will need to

chmod +x 5i25stepgens.txt

then

sudo ./5i25stepgens.txt

and all step/dir outputs should toggle at a ~ 1/3 hz rate
 

After updating the mesaflash app, I tried starting mesaflash. No errors were reported, however, the output were not toggling. Checking the man page, I could not identify any option to keep the pins toggling until the app was cancelled. Since the electronics are located on the back of the machine it requires more that 1-3 secs to move from the keyboard to the board to measure the outputs. Checking currently running programs (ps -ef | grep mesa), no app containing the string "mesa" was running. Is there a hidden option that will keep the app running until cancelled?

However, checking all of the outputs, all voltages were sitting at 4.92 v. What are the next steps for diagnosing issues with the 7i76U?

Kind regards,

The step/dir outputs should continue toggling indefinitely.

At this point I would ask for a RMA# from Mesa and return both the 7I76U and the FPGA card for
analysis/repair/replacement.

Hi PCW;

I reinstalled the boards and then verified with halshow that all of the field input switches were functioning correctly. With the spindle located in the middle of the table I started the homing sequence. Z and X both homed properly, however, when Y started the homing process a, "joint.1 failed to unhome" message was presented 3 times then joint.1 began to home while joint2. failed to move.

The machine is configured with both the Y and the Y2 axes (joint.1 and joint.2) set up with "both limits and home" switches using a single input for each axis. Thus, neither axis home switch was triggered yet LINUXCNC could not logically unhome one of the two axes.

What is the next step to resolve this issue?

Kind Regards,

One way to debug this might be to do a halscope plot of the homing sequence.
That is, plot the home switch states and Y +Y1 motion during a home 
move.