Heater reads 2000° and error Bad Vssa

[theBAHNFreak]

Hello everyone,

I just got a fully build Voron 2.4 with an Duet 3 mini 5+ WiFi and an External toolboard 1lc. Since the last print it says:
Heater 1 fault: failed to read sensor: bad Vssa
after restart. The temperature Von Heater 1 ist than shown as 2000°C witch sets the Heater in to fault.

Hopefully someone of you has an idea what's going on and can help me. Feel free to ask for needed information and I will try to tell you.

Greatings

theBAHNFreak

[dc42]

@theBAHNFreak the "Bad VSSA" message usually means that there is a short circuit between the thermistor and the hot end heater. A less likely possibility is that the VSSA PTC fuse on the tool board has failed or it is not soldered properly.

If you disconnect the hot end heater from the tool board, do you get a room temperature reading?

[theBAHNFreak]

@dc42 After unplugging the heater it still say 2000°. I made sure it is an thermistor an the config sets the input correctly.
Last I exchanged the toolboard but still got the wrong temperature reading. Maybe its an cable problem of the bus cable to the Mainboard ?

[Phaedrux]

@theBAHNFreak said in Heater reads 2000° and error Bad Vssa:

Last I exchanged the toolboard but still got the wrong temperature reading.

Is the new toolboard running the same firmware?
What is the temperature reading now?

[Poglitst]

@theBAHNFreak I had a similar Issue with a Toolboard 1LC v1.2 after disconnecting everything from the board I still got the same bad Vssa error so I checked the schematics and measured the board. I found that the Resistor R47 had a value in the range of 2.2kOhm instead of 10Ohm and replaced it. After that, the temperature reading on both temp0 and temp1 was working.