Duet 2 maestro keep resetting power supply

dc42

@cecil, my guess is that your heater cartridge has an intermittent short circuit, either across the element or between the element and the casing, that occurs when the element is hot. Try a new heater cartridge.

Cecil

@dc42 But it keeps doing also with disconnected heater. So it's switching power to open circuit and also it's failing.

dc42

@cecil said in Duet 2 maestro keep resetting power supply:

@dc42 But it keeps doing also with disconnected heater. So it's switching power to open circuit and also it's failing.

OK. Are you sure there is nothing conductive underneath the Duet that could be shorting the heater output pins together? Or some metallic swarf landed on top of the Duet?

The Maestro has two connectors per hot end heater output: a 2-pin Molex KK connector, and a 2-pin terminal block. Are you sure you have nothing connected to either of them?

Cecil

I really don't see anything what could cause the issue. And as I say it is strange because when I connect multimeter it shows me just 1.7A, only thing what could be causing it is some kind of current spike, but why?

Phaedrux

Are the heat sinks on the bottom shorting something?

Cecil

@phaedrux No, but I'll try o take them down. I haven't tried it yet. But they are there for a longer time than I have the issue.

Yesterday I put back RRF, I made some minor adjustment from last setting (for new extruder/hotend) and tried to calibrate PID on hotend. It made a good test because it's heating on full power. And it passed! 🥳 No issue at all!

Then without touching board I tried to heat hotend to change filament and crap! In like 5 seconds power down again!

Phaedrux

Might be a good idea to disconnect everything, take it out entirely and give everything a cleaning. Then test it on the bench.

Cecil

@phaedrux
I'll give it another try tomorrow. I thought it was fixed somehow, it worked now 2 days without issues, but today I came and again nothing was possible to print. It is really strange because first hour it was doing pre-heating fine but after that when homing and Z was triggered it shut down power supply. Then it become in a state i wasn't able to preheat. I disconnected everything keeping just power in, heater and thermistor connected and I still cannot preheat. I'll disassembly tomorrow also power supply and put it to bench and test there. Video from today here: youtube

Cecil

@phaedrux
Took the board out, cleaned with IPA, tried several heat cycles on bench without issue, assembled back, taking care every connection is good, printed for 4 hours without issues. Today after one 0.5 hour print it's back again.

Phaedrux

Do you have a different power supply to test with?