7i73 LCD shows rubisch

So, the question has to be "what is different"

First we ought to make sure that your system is using the new version of the LCD component.
"halcmd setp lcd.00.decimal-separator 38" should set all the decimal points to "&" characters if the system has picked up the new version. (That was one of the things I fixed, it wasn't working before)

I am running a 7i80DB connected to a 7i76 connected to a 7i73. This should be really quite similar to your 7i76E
I am _not_ running a full LinuxCNC config, I find it easier to run a smaller system for development work (in fact, the HAL file I already posted) but it is possible that your system has interactions that mine doesn't. (timing is likely to be different)

My 7i73 is using firmware version "C" (show params and it is "swrevision") and LinuxCNC warns me that I should update it.

I used your file.
Switched of power of pc and mesa before.
Your config explains why I had to change the sserial port.
And for sure your config is a bit slower in throughput.
How can I readout my versions? With mesaflash?

To find the firmware version, one way is:
open a terminal

halrun
loadrt hostmot2
loadrt hm2_eth board_ip=192.168.1.121 (or whatever you use)

Then you should see some pinout info.

Then:

Show param *7i73"

To see the 7i73 parameters, one of which is "swrevision"

And, please can you try the decimal-separator switch? That's one way to be totally sure that your system is running the new lcd module version.

Can you post your current hal/ini files?
I can try and duplicate this since i have identical hardware available

I USED YOUR FILE and here some cutouts:

...............
hm2_eth: 192.168.1.121: Hardware address: 00:60:1b:10:40:be
hm2_eth: discovered 7I76E-16
hm2/hm2_7i76e.0: Smart Serial Firmware Version 43
Board hm2_7i76e.0.7i76.0.0 Hardware Mode 0 = standard
Board hm2_7i76e.0.7i76.0.0 Software Mode 0 = io_spin
Board hm2_7i76e.0.7i76.0.0 Software Mode 1 = io_ana_spin
Board hm2_7i76e.0.7i76.0.0 Software Mode 2 = io_enc_ana_spin_fv
Board hm2_7i76e.0.7i73.0.1 Hardware Mode 0 = nokeyboardnodisplay
Board hm2_7i76e.0.7i73.0.1 Software Mode 0 = inputoutputencoder
Board hm2_7i76e.0.7i73.0.1 Software Mode 1 = inputoutputencoderanalog
Board hm2_7i76e.0.7i73.0.1 Software Mode 2 = inputoutputencoderanalog
Board hm2_7i76e.0.7i73.0.1 Hardware Mode 1 = nokeyboarddisplay
Board hm2_7i76e.0.7i73.0.1 Software Mode 0 = inputoutputencoderdisplay
Board hm2_7i76e.0.7i73.0.1 Software Mode 1 = inputoutputencoderanalogdisplay
Board hm2_7i76e.0.7i73.0.1 Software Mode 2 = inputoutputencoderanalogwidedisplay
Board hm2_7i76e.0.7i73.0.1 Hardware Mode 2 = keyboard4by8nodisplay
Board hm2_7i76e.0.7i73.0.1 Software Mode 0 = inputoutputencoderkeycode4by8
Board hm2_7i76e.0.7i73.0.1 Software Mode 1 = inputoutputencoderanalogkeycode4by8
Board hm2_7i76e.0.7i73.0.1 Software Mode 2 = inputoutputencoderanalogkeycode4by8
Board hm2_7i76e.0.7i73.0.1 Hardware Mode 3 = keyboard4by8display
Board hm2_7i76e.0.7i73.0.1 Software Mode 0 = inputoutputencoderdisplaykeycode4by8
Board hm2_7i76e.0.7i73.0.1 Software Mode 1 = inputoutputencoderanalogdisplaykeycode4by8
Board hm2_7i76e.0.7i73.0.1 Software Mode 2 = inputoutputencoderanalogwidedisplaykeycode4by8
Board hm2_7i76e.0.7i73.0.1 Hardware Mode 4 = keyboard8by8nodisplay
Board hm2_7i76e.0.7i73.0.1 Software Mode 0 = inputoutputencoderkeycode8by8
Board hm2_7i76e.0.7i73.0.1 Software Mode 1 = inputoutputencoderanalogkeycode8by8
Board hm2_7i76e.0.7i73.0.1 Software Mode 2 = inputoutputencoderanalogkeycode8by8
Board hm2_7i76e.0.7i73.0.1 Hardware Mode 5 = keyboard8by8display
Waiting for component 'hm2_eth' to become ready.Board hm2_7i76e.0.7i73.0.1 Software Mode 0 = inputoutputencoderdisplaykeycode8by8
Board hm2_7i76e.0.7i73.0.1 Software Mode 1 = inputoutputencoderanalogdisplaykeycode8by8
.Board hm2_7i76e.0.7i73.0.1 Software Mode 2 = inputoutputencoderanalogwidedisplaykeycode8by8
.......hm2/hm2_7i76e.0: 51 I/O Pins used:
hm2/hm2_7i76e.0: IO Pin 000 (P1-01): StepGen #0, pin Direction (Output)

..................

7 s32 OUT 2098000000 hm2_7i76e.0.0.debug
7 float OUT 1.656471 hm2_7i76e.0.7i73.0.1.analogin0

7 float OUT 23.60954 hm2_7i76e.0.7i76.0.0.fieldvoltage

7 float IN 1 hm2_7i76e.0.dpll.base-freq-khz
7 u32 OUT 0x0000002A hm2_7i76e.0.dpll.ddsize
7 float OUT -3.622883 hm2_7i76e.0.dpll.phase-error-us
7 u32 IN 0x00400000 hm2_7i76e.0.dpll.plimit
7 u32 OUT 0x00000018 hm2_7i76e.0.dpll.prescale
7 u32 IN 0x000007D0 hm2_7i76e.0.dpll.time-const

7 bit OUT FALSE hm2_7i76e.0.packet-error
7 bit OUT FALSE hm2_7i76e.0.packet-error-exceeded
7 s32 OUT 0 hm2_7i76e.0.packet-error-level
7 s32 OUT 0 hm2_7i76e.0.read-request.time
7 s32 OUT 723640 hm2_7i76e.0.read.time
7 u32 OUT 0x00000000 hm2_7i76e.0.sserial.port-0.fault-count
7 u32 OUT 0x00000003 hm2_7i76e.0.sserial.port-0.port_state
7 u32 OUT 0x00000000 hm2_7i76e.0.sserial.port-0.port_state2
7 u32 OUT 0x00000000 hm2_7i76e.0.sserial.port-0.port_state3
7 bit IN TRUE hm2_7i76e.0.sserial.port-0.run

7 bit OUT FALSE hm2_7i76e.0.packet-error
7 bit OUT FALSE hm2_7i76e.0.packet-error-exceeded
7 s32 OUT 0 hm2_7i76e.0.packet-error-level
7 s32 OUT 0 hm2_7i76e.0.read-request.time
7 s32 OUT 723640 hm2_7i76e.0.read.time
7 u32 OUT 0x00000000 hm2_7i76e.0.sserial.port-0.fault-count
7 u32 OUT 0x00000003 hm2_7i76e.0.sserial.port-0.port_state
7 u32 OUT 0x00000000 hm2_7i76e.0.sserial.port-0.port_state2
7 u32 OUT 0x00000000 hm2_7i76e.0.sserial.port-0.port_state3
7 bit IN TRUE hm2_7i76e.0.sserial.port-0.run

..................

7 u32 RW 0x00000001 hm2_7i76e.0.7i73.0.1.hwrevision
7 u32 RW 0x00000000 hm2_7i76e.0.7i73.0.1.keymode
7 u32 RW 0x00008000 hm2_7i76e.0.7i73.0.1.nvanalogfilter
7 u32 RW 0x00000009 hm2_7i76e.0.7i73.0.1.nvbaudrate
7 u32 RW 0x00002710 hm2_7i76e.0.7i73.0.1.nvcontrast
7 u32 RW 0x00000414 hm2_7i76e.0.7i73.0.1.nvdispmode
7 u32 RW 0x00000000 hm2_7i76e.0.7i73.0.1.nvencmode0
7 u32 RW 0x00000000 hm2_7i76e.0.7i73.0.1.nvencmode1
7 u32 RW 0x00000000 hm2_7i76e.0.7i73.0.1.nvencmode2
7 u32 RW 0x00000000 hm2_7i76e.0.7i73.0.1.nvencmode3
7 u32 RW 0x0000001E hm2_7i76e.0.7i73.0.1.nvkeytimer
7 u32 RO 0x130000B2 hm2_7i76e.0.7i73.0.1.nvunitnumber
7 u32 RO 0x00000032 hm2_7i76e.0.7i73.0.1.nvwatchdogtimeout
7 bit RW FALSE hm2_7i76e.0.7i73.0.1.output-00-invert

7 u32 RW 0x0000000E hm2_7i76e.0.7i76.0.0.swrevision

7 bit RW FALSE hm2_7i76e.0.io_error
7 s32 RO 1 hm2_7i76e.0.packet-error-decrement
7 s32 RW 2 hm2_7i76e.0.packet-error-increment
7 s32 RW 10 hm2_7i76e.0.packet-error-limit
7 s32 RW 80 hm2_7i76e.0.packet-read-timeout
7 s32 RW 0 hm2_7i76e.0.read-request.tmax
7 bit RO FALSE hm2_7i76e.0.read-request.tmax-increased
7 s32 RW 817264 hm2_7i76e.0.read.tmax
7 bit RO FALSE hm2_7i76e.0.read.tmax-increased
7 bit RW FALSE hm2_7i76e.0.sserial.00.tx0.invert_output
7 bit RW FALSE hm2_7i76e.0.sserial.00.tx0.is_opendrain
7 bit RW FALSE hm2_7i76e.0.sserial.00.tx1.invert_output
7 bit RW FALSE hm2_7i76e.0.sserial.00.tx1.is_opendrain
7 u32 RW 0x00000001 hm2_7i76e.0.sserial.port-0.fault-dec
7 u32 RW 0x0000000A hm2_7i76e.0.sserial.port-0.fault-inc
7 u32 RW 0x000000C8 hm2_7i76e.0.sserial.port-0.fault-lim

.........................

7 u32 RW 0x004C4B40 hm2_7i76e.0.watchdog.timeout_ns
7 s32 RW 42088 hm2_7i76e.0.write.tmax
7 bit RO FALSE hm2_7i76e.0.write.tmax-increased
10 u32 RW 0x0000002E lcd.00.decimal-separator
10 s32 RW 1992 lcd.tmax
10 bit RO FALSE lcd.tmax-increased
14 s32 RW 854656 thread1.tmax

.........................
Exported Functions:
Owner CodeAddr Arg FP Users Name
00007 7f46425c76cf 55da5ff309d0 YES 1 hm2_7i76e.0.read
00007 7f46425c765f 55da5ff309d0 YES 0 hm2_7i76e.0.read-request
00007 7f46425c757c 55da5ff309d0 YES 1 hm2_7i76e.0.write
00010 7f46421b87cb 7f46445f3398 YES 1 lcd

Realtime Threads:
Period FP Name ( Time, Max-Time )
1000000 YES thread1 ( 721120, 854656 )
1 hm2_7i76e.0.read
2 lcd
3 hm2_7i76e.0.write

7 u32 RW 0x0000000E hm2_7i76e.0.7i76.0.0.swrevision

That's newer than mine, I can try updating. But I suspect that PCW would have mentioned if there had been any LCD updates in the firmware?