@macsbug Thanks for responding.
I have tried those two solutions and it didn't work:

1. M5Burner - erase flash, burn UI-Flow
2. M5Burner - erase flash, burn Core2FactorTest; I actually think it was this program that initially killed my display driver; I have two new m5Core2's and I wonder if this programs is installing the wrong display drivers for my new Core2.
3. M5Burner - erase flash, burn M5Core2TouchPanelRecovery; I also tried this program but it was hard to use as I couldn't see the display menu; I used the power button to blindly select each of the two firmware drivers and to load them.

@teastain Thanks for asking.
I can use Arduino-IDE or UI-Flow-Desktop-IDE. I have also downloaded Thonny and ESPTools. So far the following has not worked to fix the display:

1. M5 Burner ==> erase flash, and burn UI-Flow
2. M5 Burner ==> erase and burn Core2FactoryTest
3. M5 Burner ==> erase and burn M5Core2TouchPanelRecovery
4. ESPTools ==> download 16MB flash image from a working m5core2 and flash to the problematic m5core2.
5. Use "EasyLoader" to burn a program to test all core2 functions per the link on https://docs.m5stack.com/en/core/core2

What is strange is that the only thing not working is the display. The backlight comes on. I can program the three buttons to send sounds to the speaker. I can create button on the touch screen that activate though I can't see them. If I print a label to the screen the device will freeze.

I have a 1 week old M5Core2 that is having display driver problems - but everything else seems to work.

What is the procedure to re-flash my M5Core2 back to the pre-installed factory firmware. I see there is a github file on how to do this but only for the AWS version of the M5Core2.

Re: M5Core - blank screen

Hello, I have the same issue with M5Core2. The device worked for a couple of days, but now screen is blank. I've tried the following all without success: (i) erasing flash and reloading the UI-Flow Core2 firmware, (ii) erasing flash and loading the Core2FactoryTest, (iii) erasing flash and loading the M5Core2TouchPanelRecovery, (iii) used "Firmware Exporter" from M5Burner to save the 16MB binary image of a good working M5Core2 and then used ESPTools to burn that image onto the broken M5Core2.

I am curious if you have found a solution to your similar blank screen problem.

I have two new M5StackCore2 devices; and the screen has gone blank on one unit after I loaded the Demo program.

I was able to use M5Burner to burn UIFlow_Core2 and to try some simple UI_Flow blockly programs successfully. I was able to program ButtonA and ButtonB to show different messages on the screen.

I tried to download the demo program and my Core2 screen went blank.

I have tried the following fixes unsuccessfully:

• used M5Burner to erase flash and burn a new copy of UIFlow_Core2
• used M5Burner to erase flash and load Core2FactoryTest (I read on the forum that can be a problem)
• used M5Burner to load M5Core2TouchPanelRecovery (my screen was blank, so I had to blindly use the power button to go through the two selections to write new model FW)

At this point I can write small blockly test programs that use Button A and Button B to cycle the vibrator on and off - which seems to imply everything else is working. However if I add a simple block to write a single label to the screen, I see nothing on the display (and the button test code will stop working to use Button A/B to cycle the vibrator).