Hotend Test Immediate Failure
I just put together this Core One model, everything went well when setting up, all tests passed up until the eighth test -- heating. Heatbed works fine and passes every time. Nozzle heat is evaluated as a failure almost as soon as the test starts. Manually increasing the nozzle heat creates the exact same result, causing a forced shutdown and gives error #31202. The error page is not very helpful IMO, but overall every connection on the nextruder and loveboard are correct and there is no apparent damage to any cables. Help on this would be greatly appreciated.
RE:
When you manually increased the nozzle temperature, did it get hot or stay cold? If it did get hot followed by a failure then perhaps the thermistor is bad. It's always a good idea to have spare hot end thermistors and heating elements. I use non-Prusa branded ones from Amazon that work fine.
If this is page you are referring to I think the instructions are pretty good: Hotend preheat error