LTS will not boot with 7" LCD connected

[GregH]

Just received my A64 LTS with Playbox and 7" LCD from Pine after many delays (another story). Very excited!

My LTS boots fine (eMMC) with Armbian Buster and an HDMI monitor connected. I'm powering via the supplied 5V/3A barrel connector ps. However with the LCD DSI cable attached, the LTS will not boot - the green power light comes on, dims slightly, then goes out after a couple of seconds.

It seems I'm not the only one with this issue:
https://forum.armbian.com/topic/8392-pin...ment-95229

After plugging everything together I inserted the DC barrel jack (original 5V 3A power supply) and then the LED goes on only for 1-2 seconds and then goes off.

Does this seem like a hardware issue? On that discussion, someone mentioned a similar issue until they used a swapped out the A64 board.

On advice from the Pine Support Team I double-checked that I had the latest Armbian image (5.4.20) and re-downloaded it for a re-flash. No change.
I have since attached a battery and swapped the jumper on power select jumper to select BAT. The LTS now boots with the LCD DSI & TS cables connected, but I get a problem during boot which tells me:

Code:

Failed to start Load Kernel Modules.
See systemctl status systemd-modules-load.service

Which reveals:

Code:

? systemd-modules-load.service - Load Kernel Modules
   Loaded: loaded (/lib/systemd/system/systemd-modules-load.service; static; vendor preset: enabled)
  Drop-In: /lib/systemd/system/systemd-modules-load.service.d
           +-10-timeout.conf
   Active: failed (Result: exit-code) since Sun 2020-03-22 23:17:58 UTC; 1min 32s ago
     Docs: man:systemd-modules-load.service(8)
           man:modules-load.d(5)
  Process: 555 ExecStart=/lib/systemd/systemd-modules-load (code=exited, status=1/FAILURE)

 Main PID: 555 (code=exited, status=1/FAILURE)
Mar 22 23:17:58 pine64so systemd[1]: Starting Load Kernel Modules...
Mar 22 23:17:58 pine64so systemd-modules-load[555]: Failed to find module 'gt9xxf_ts'
Mar 22 23:17:58 pine64so systemd[1]: systemd-modules-load.service: Main process exited, code=exited, status=1/FAILURE
Mar 22 23:17:58 pine64so systemd[1]: systemd-modules-load.service: Failed with result 'exit-code'.
Mar 22 23:17:58 pine64so systemd[1]: Failed to start Load Kernel Modules.

For some reason the gt9xxf_ts module isn’t found.
Also note that when I edit /boot/armbianEnv.txt, the pine64_lcd line isn’t present as implied by the note in the instruction “Change off to on”.

Any ideas?