Really basic question about my TwoTrees Sapphire Plus printer firmware

This is an extension of other threads pertaining to my efforts to get my Sapphire Plus working. The folks at TwoTrees have asked me to reload the original firmware that came with the printer. Okay, so, I put the flash drive that came with the printer into the slot and started it up. Didn't seem to have any effect, at least it didn't affect the problem I'm having. (when homing the Z axis, the printer doesn't stop when it hits the limit switches).

So, a couple of questions. Which file has the firmware on it? I found a file called robin_non35_cfg.txt file that's in the "firmware" folder. There is also a file called robin_nano35.bin in one of the subfolders. Does it need to be in the root of the flash drive to be found on startup?

Like I said, very basic stuff, but the first time I'm trying to do it.

Thanks. Ron

More news....

I was able to find enough information to be able to flash the firmware on the printer.

I went to the TwoTrees website and got the latest firmware, which is V2.0.3.A. I loaded this onto the printer and the update seems to have worked.

First thing is that the display is now upside down.

when testing homing.....
The x-axis goes to the far left, which I think is correct.
The y-axis goes to the rear of the printer, which I think is okay.
When doing a home on the Z-axis, the extruder head moves to the front right corner of the printer. The hot bed rises and crashes into the limit switches.

Sent a video of this to TwoTrees, and asked for next steps. I'm going to double check cables and such, but I've done that before, although Twotrees told me that the manual actually has the position of the "filament sensor" cable in the wrong place, and had me move it to the "power failure socket". Probably isn't affecting the z-axis homing, but that's where we are.

It seems to be ignoring both of the z-axis limit switches, but I'm not sure exactly what that's telling me, other than either the cables are wrong, or something in the software is telling the printer to ignore the z-axis limit switches. I can check the cables, but I'm not sure how to check the software to see if something is telling the limit switches to be ignored, and if so, how to fix it. In the config text file, maybe? but what would you do with that?

Any thoughts?

Thanks. Ron