7i92TM defect? How to verify?

Hello,
I would appreciate a second thought on an issue I experience with the 7i92TM. The board is connected to a G540. After installing linuxcnc 2.9 and some rearrangement of hardware, I only have two axis left functioning (z and y) and switches (connected to the G540) are not recognized anymore either. 
Swapping the wiring to other axis transferred the functioning axis over to the new config. 
I was suspecting the G540 to be at fault and swapped it against a chinese parport BOB I still had around.
After flashing the 7i92 with the correct file (5abobx2), the new setup shows the same behavior as before which pretty much rules out the G540. 

I am running out of ideas and hence considering the 7i92TM being the problem. 
I measured the voltage of Step+ to ground and Dir+ to  ground with Linuxcnc running directly at the BOB. Results as shown below. 

Xstep: 5V
Xdir: 0V
Ystep: 5V
Ydir: 5V
Zstep: 5V
Zdir: 5V
Y2step: 0V
Y2dir: 0V

Is my assumption correct that, since z and y axis do have 5V on step and dir an the others don't, that these are outputs are physically damaged?

Thanks for your help. 


 

A quick way to test is with mesaflash:

Disconnect the 7I92TM from breakouts/ G540 and make sure the
pullup option on P2 is enabled (W2 UP) Then in a terminal window:

mesaflash --device ethernet --addr 10.10.10.10 --rpo 0x1000

(replace 10.10.10.10 with 192.168.121 if you card is set that way)

This should respond with

0001FFFF

(all 17 I/O bits high)

Thanks a lot.
I am getting 00001000 as a response.

what does

mesaflash --device ethernet --addr 10.10.10.10 --rpo 0x1004


report?

(that's the second port)

 

00008000

If you measure the voltage across C36 I expect you will find a low voltage
instead of the expected 4.2V. What this likely means is that one or both
bus switch parts (74CBT16211) have been damaged by either ESD
or by being connected live to the G540 with no common ground
existing between the G540 and 7I92T before they were connected,
exposing the bus switches to a transient high voltage.

Thanks a lot. I was afraid to hear this but at least I know where I stand now.