I got a used TAZ4 the other day and got sucked down many rabbit holes while trying to find a bed leveling print to calibrate the printer. (Found it and all other mentioned downloads from the manual here btw… LulzBot | Downloads) Long story short I updated the Marlin firmware to 1.1.1.9. I did this through the newest version of Cura. I identified my printer as a TAZ5 single extruder and the firmware updated. Then I figured out Cura wouldn’t be compatible even with this update, so I reverted to a previous version of Cura as recommend on another thread. At this time I went to preheat my bed and nozzle and noticed the nozzle wasn’t raising in temperature according the display but the bed was. I quickly received an “e1 heating failed printer halted please reset.” I’ve visually investigated for damaged parts and disconnected/reconnected the connectors but no fix. I am now working to revert back to original Marlin the TAZ4 came with via Arduino IDE and hope that could help. I never managed to print anything on the printer, but the day before updating I had brought the nozzle/bed up to temperature and back down so I know it worked when I received it.
Is this all a coincidence or is firmware the issue?
It could be firmware. Looking at the CuraLE 21.08 firmware folder (see below) most of the files appear to be for the TAZ4-5. A picture of the extruder could help identify what type it is.
These machines were sold partially on the premise that they are easily modified, and so there’s a good chance that a almost 10-year old Taz4 is no longer stock. There could be any number of modifications done to that required custom wiring and firmware. A thorough set of pictures of the machine’s current state, as well as a shot of the motherboard could help determine if you have anything resembling a Taz 4 that would work with official firmware for it or the 5.
But easy things first:
Does your screen show the temperature of the hot end when at idle, or just 0°/0°? If it’s 0°/0°, the thermistor is broken, or not wired according to what the firmware is configured for.
if it’s 0°/27° (or whatever your ambient temp is), at least the thermistor is working, and it would be likely that your heater is broken, or not wired according to what the firmware is configured for. The soldering on the motherboard for the heater is also known to fail and burn out, so it could have been brittle when you last used it, and burnt out or cracked to an open position when it cooled off. You’d have to inspect motherboard to see if this was it.
If you see three set of numbers (0°/27° 0°/0° 0°/27°), you’ve got dual extruder firmware loaded, and marlin 1 doesn’t like that when you only have a single hot end.
If it says E1 failed, you have dual extruder firmware. E0 is the first extruder. Right?
In marlin 2.x, in the code, it’s E0 for the first extruder and E1 for the second, but I can’t guarantee it was that way in the version that he’s running. There seems to be inconsistency in referring to the hot ends in general, but definitely in how they’re referred to internally, and in error messages on the user-facing side.
