Help with mesa 7c81 and 7i77 setup. Possibly corrupted flash

Hi folks,

I'm trying to set up a mesa 7c81 with 7i77 board and I'm afraid I may have messed up the board.  Hopefully somebody can guide.

I'm using a 7c81 with raspberry Pi 4 /8G    (I purchased this unit a couple years ago but I'm only getting around to setting it up now)
Linuxcnc 2.8.1 (linuxcnc-2.8.1-pi4.zip)

Power is supplied to the 7i77 via the 25pin connector from the 7c81 and field power (24v) on the 7i77 is connected.

I tried creating a couple of configs with pncconf and had a problem

hm2/hm2_7c81.0: config.num_encoder=6, but only 1 available

From some research it seems like I needed to flash the 7c81 for the 7i77  (maybe I went wrong here? )

From the mesa page I got the support software www.mesanet.com/software/parallel/7c81.zip
Got mesaflash version 3.4.7 from git (and did make) but unfortunately I forgot to directly address the newly downloaded mesaflash and the version that ran was actually 3.4.6

I did:

pi@apeiron:~/linuxcnc/7c81/configs/hostmot2 $ mesaflash --device 7C81 --spi --addr /dev/spidev0.0 --write 7c81_7i77x2d.bit
unable to set bpw32, fallback to bpw8
Checking file... OK
  File type: Xilinx bit file
Boot sector OK
FLASH memory sectors to write: 6, max sectors in area: 32
Erasing FLASH memory sectors starting from 0x200000...
  |EEEEEE
Programming FLASH memory sectors starting from 0x200000...
  |WWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW
Board configuration updated successfully.
Checking file... OK
  File type: Xilinx bit file
Boot sector OK
Verifying FLASH memory sectors starting from 0x200000...
  |V0 timeout waiting for SPI data

Error at 0x203D4B expected: 0x0 but read: 0x7F


pi@apeiron:~/linuxcnc/7c81/configs/hostmot2 $ mesaflash --device 7C81 --spi --addr /dev/spidev0.0 --write 7c81_7i77x2d.bit
unable to set bpw32, fallback to bpw8
Unexpected cookie at 0100..0110:
0fff0fff 0fff0fff 0fff0fff
No 7C81 board found


Even after power cycle same issue - unreadable when it worked before.  For example this used to work:
mesaflash --device 7C81 --spi --addr /dev/spidev0.0 --readhmid
unable to set bpw32, fallback to bpw8
Unexpected cookie at 0100..0110:
9fff1fff 1fff1fff 1fff1fff
No 7C81 board found

(I'm attaching the --readhmid  output from when it worked.)

The lights on the board I think show that it is on the main bootfile and not the fallback. (init isn't blinking)

It seems to me like I've messed up the 7c81 and perhaps the only fix is through the jtag port? (not that I know how to do that).  

I'd appreciate any guidance you might have. 
 

If you don't have any red LEDs illuminated on the 7C81 after power up
that means that a valid configuration loaded. It actually looks like something
went bad (power, cabling, 7C81,RPI) at the start of verification before the new
firmware was even used. So I don't think this is a firmware issue.

I thought about the ribbon cable between the rpi and the 7c81 but I never touched it physically when this happened and it is consistently bad at this point. Just tried jiggling it (w/ power off) but no luck.

Just checked the power - it was a little low 4.8v so I just adjusted it up to 5v but not luck.

So it is likely that the board is working but the rpi can no longer talk to it?

I guess I have two options to test:
1) replace the ribbon cable between the two
2) replace the rpi with another (I think I have one I could swap in)

I should have made this all more easily serviceable

I tested with another rpi 4 and with a fresh install of linuxcnc but no luck.

I need to check replacing the cable now. I think I have the parts to make one.

They don't appear to be in stock at store.mesanet.com/
I'd buy another 7c81 at the same time but also not in stock, nor the 7c80

If you are in USA also check
www.mesaus.com
If in Europe,
www.eusurplus.com

In Canada but often companies will ship here. Seems they are out of the 7c81 but good to know other sources.