Touchscreen works but doesn't do anything

I busted my old LCD screen on my Monoprice rebranded Wanhao Duplicator i3 Plus, so I decided to replace it with a new one. I flashed it with 4.0.4. It did get stuck after flashing (just wouldn’t go to the main menu) but I figured since this was my first time using ADVi3++ that was normal. I flashed the mainboard with 4.0.4. Mainboard flash went fine. The LCD showed the “EEEPROM settings not compatible” warning until I disconnected the printer from USB.

I rebooted the printer and the menu loaded up flawlessly. I can touch all the buttons and they light up as if they’ve been pushed, but nothing happens. Temperature monitor on the main screen shows correct data. I re-flashed the LCD and the mainboard with 4.0.4 and the issue persisted. I tried to downgrade the LCD to 4.0.3. It still reads 4.0.4. The screen is not “bricked”, just not doing anything after each button push. I did try the 4.0.5 calibration image (Since I can’t reach calibration normally), and calibration went fine. Those controls responded.

I tried flashing to 4.0.5. Screen still says 4.0.4. I can control the printer via USB fine.

I’m basically out of ideas at this point. Any suggestions? Cable was working fine with old LCD, but if you suspect my cable from mainboard to LCD is bad, can anyone tell me the specifications (pitch, pins) to replace it?

Which model exactly?

This is normal. The mainboard part is still at version 4.0.4, and this is what is reported on the screen.

What you described looks like if the LCD panel is receiving command from the mainboard, but does not send commands back to the mainboard. It could be that the cable is not well inserted into its sockets.

It is a standard 10 pins FFC 1.0 mm.

I replaced it with the exact model that the old one was. DWIN DMT48270M043_02WT.

I checked the continuity across the ribbon cable. All seems good.

I tried hooking up the old LCD and it will respond to button presses and allow me to navigate the menus but since the mainboard is newer now it won’t preheat or read the SD card or anything.

By the way, the screen does dim after a while and re-light if you press anything.

Could one of the connectors on the screen itself be defective in this case? Commands maybe not getting from the button pushes into the mainboard?

Button presses (the fact that the button change under press) are handled by the LCD panel itself.

This is handled by the mainboard. So it means your cabling is correct.

This is handled by the mainboard. So the mainboard is receiving something from the LCD panel.

It looks like the connectors are OK (since both the LCD and the mainboard are communicating). So more probably, your new screen is defective. Maybe the flat, rigid cable between the top of the screen and the back is damaged.

In your expert opinion, is this the only possibility you see? Is there no possible way this could be a software issue after describing what each screen is capable of? I would like to eliminate all possibilities you can think to test if I’m in fact going to need a new screen.

Actually, I just noticed. My old board has a solder between a couple of contacts in the upper left that the new one does not have. Some kind of jumper near a chip.

Well… I took the new screen off the new board and put it on my old board in place of my broken screen and flashed it. Wouldn’t you know it, works like a charm. I guess it’s time to ask for a refund on that part.