@Phaedrux I've resettled my TC and heater and it looks like one of the heat block screws was the culprit. I'm reluctant to run the printer without it though - the heater and/or TC might come off the block during print.
I'm now running M303 and it looks okay.
I only have an issue now with the print bed - it faults because of expected temperature rise is too low, but I'm assuming it can be modified in config.
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Controversial posts made by ov_darkness
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RE: Heater fault when trying to enable tool