[BUG] just updated to v2.1.9-rc (Marlin 2.0.x) and printer shuts down as turned on

[scalda]

Bug Description

I have just finally got around to sorting and upgrading my 4max pro, and decided to give your firmware a go during the process.

So I have uploaded v2.1.9-rc (Marlin 2.0.x) to the printer but as soon as I turn it on and it begins to start up the I hear the relay click and the printer shuts off

My Configurations

default as of v2.1.9-rc (Marlin 2.0.x)

Steps to Reproduce

1. update to v2.1.9-rc (Marlin 2.0.x)
2. turn printer on with blue button
3. print shuts off before the logo finishes on the screen

Expected behavior: printer to turn on correctly ready for printing

Actual behavior: printer turns off when turned on with blue button

Additional Information

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[scalda]

i've found if i unplug the iic cable from the mainboard to the PSU relay board it boots fine but I no longer get any temps showing

[scalda]

fixed the issue was a bad thermistor no idea how but it was sorry to take up your time