I'm having the same problem as Rob above. I purchased a key on 12/20/2019, and tried following the steps in the Noinks guide. At every attempt, the Noinks updater fails with "Update Failed". (Once, it showed "Your firmware is already updated", but upon retry, went back to "update failed")
I've tried flashing the WFC5710_FWG239TL_ZZ99Z9.zip firmware using the original instructions (power off, 4+7+Job/Status), as well as the revised instructions to run it under normal mode.
Results: Firmware update mode: Enters mode just fine, displays white text. Says "PRINTER UPDATE MODE", then "CU06" in middle of screen. Upload proceeds, then finishes with "FINISHED, ROM VERSION 16.54.CU26I9, ROM1 FIXSUM 2E07, ROM2 FIXSUM 6C60". After this, all lights flash at about 1 second intervals, but unlike guide, pressing the center of the LCD (or anywhere else or any other button) doesn't reboot the printer. I have to pull the plug at this point. (I have tried leaving it alone for 30 min+, but it never reboots.)
Running NoInks updater at this point fails with "Update Failed".
Trying again with the printer in normal mode, firmware uploads, printer reboots by approx 71% on the progress bar. Status shows new firmware installed. If I kill the firmware updater at this point, the NoInks updater still fails with "Update Failed". If I let the normal mode firmware updater run all the way to 100%, it finally fails with a message about "firmware not installed" (It's been a few days since I let it run all the way through -- that was the jist of the message.)
Any ideas at this point?
Is there a way to verify that the chipless firmware is actually installing? Does the displayed firmware version actually change? I've tried printing status sheets after the supposed update, and get firmware version 16.54.CU26I9 Is this correct for the chipless version?
Any help would be appreciated.