sudden temperature drop at start (fan off...)

[Erik_Es 3]

An UM1 which has been working fine for over 2 years recently developed a problem: after preheating until temperature is stable, the temp measurement suddenly drops by about 6 degrees the moment the printer starts moving towards the home position. The fan is off, so that's not it.

It causes terrible temp swings in the bottom layer, as you would expect. After a while the temp balances out again, but I'm not sure whether the temperature is actually right then...

Any ideas ?

[ultiarjan 1,223]

to be honest I don't know... but when it happens at the first movement my first thought is to check cables and connectors from the sensor and heater. Another thought is that the sudden extra power consumption may have something to do with it? just thinking out lout...

[Erik_Es 3]

Cables & connectors are OK, don't see any problems during printing, even when fiddling with the wires quite shamelessly.

Power supply might be the problem, I'll check that.

Thanks