Centauri Carbon TL4980 - printhead anomaly detected, won't finish calibration

Issue

On some well-used TL4980 Centauri Carbon printers, when homing, or doing levelling, the printer may stop with an error message: Printhead anomaly detected. The error message may also appear when the print head moves to the front-left corner after you command Calibration->Automatic Levelling. 

If you have factory-reset the printer, this message below may also appear after the Input Shaping step, when the printer sends the print head into the front corner to begin levelling.

Cause

The USB-C cable that plugs into the top of the print head may have failed. Moving the print head to the front corner of the printer stretches the cable to the maximum travel distance, and in very rare cases, may cause it to fail. 

Confirming the cause

• Switch off the printer, unplug the power, close the door, & remove the top lid

• Remove the screws holding the USB-C cable to the print head (2x 1.5mm hex)

  

• Unplug the USB-C cable from the top of the print head 

• Carefully tip the printer onto its left side to expose the bottom plate

• Undo the 10x 2mm hex screws and remove the bottom plate 

  

• Unplug the USB-C cable from the mainboard (it's next to the flat ribbon screen cable)

  

• Grab another 1m or longer USB-C to USB-C cable (e.g. Cat # WC5100)

• Connect the cable plugs to the mainboard USB-C socket and the print head socket 

• Tip the printer carefully upright, connect the power cable & power it on

• Do Calibration -> Automatic Levelling to see if it works OK with the new cable 

  

Running the USB-C cable outside the printer is fine for just this test. Keep it away from the print head guide rods and belts. Warning: Don't touch any of the exposed boards or cables in the printer base whilst it is plugged-in and powered-on! When you are done testing, switch it off & unplug the power before you tip it over.

If the replacement cable did not fix the issue, you can test the print head PCB (Cat # 001768) and mainboard (Cat # 001765) by following the guide here.

How to fix

Replace the USB-C cable with a new one (Cat # 001767). Follow the replacement guide here. 

Tip: Tie a loop of string or floss around the mainboard-end plug of the old cable before you pull the cable up and out of the channel at the back right-hand corner of the printer. Once the cable is pulled out, untie the string and leave it in place, so you can tie it to the mainboard-end plug of the new cable to pull it down.