TAZ 5 X Y Z cycling "?"

I have a TAZ5 that I just purchased off ebay (yes another one of those poor used and abused TAZ5 specials you find no-where else!) :confused:

Besides the physical damage to the frame it endured during shipping (what else is new), I’ve been trying to evaluate the electronics side of it.

When I power the printer on, the X Y and Z displayed on the LCD screen cycle between "X,Y,Z and a ? mark. Does anyone know what that means?

I’ve checked the wiring and the control board, and it appears physically to be in ok shape.

With the build in controls, I can move the X, Y and Z axis steppers, and the heated bed and extruder heats up… BUT… I cannot get the extruder stepper to do anything. I’ve checked the wiring and it’s ok. I’ve swapped in a known working print head, and the stepper to extrude filament will not do anything when told to do so from the control panel.

Any thoughts?

Thanks for your time and reading about my woes…


The LCD screen will show ?'s for all axis until the printer is homed. Once an axis is homed, it will then give a reading.

Thanks for your reply, but I can’t say that I see that behaviour on any of my other four TAZ5 printers.

I can’t seem to move the extruder motor through the LCD panel/controls, however, I can control the X,Y,Z axis steppers through there.

I also can’t seem to connect to the rambo board with any PC or astrobox. Tried machines/astrobox’s that are working on my other printers.

Wonder if perhaps the rambo board is cooked. Think that’s plausible?

Any thoughts?


it likely has new firmware thats why you dont see it on your others. Also since firmware is newer the baud rate is now 250,000