Duet with PC PSU and pwr_on sometime just switches off ?

I have a sporadic issue with the Duet or the power supply.

Very sporadic the Duet is switching off and directly powering again (by putting 12V to the pwr_on pin -> PC PCU) is not directly working or
the Duet is turning off after 2 seconds again.
But mostly it works as expected.

Today the Duet switches off during a print job, it has been printing for ~3 hours already and than when turning movement from forward to backward it
happens.

My heatbed is AC using an SSR, the hotend was heating, I have 2 always on fans, PanelDue one Nema17 for X-axis and one Nema23 for Y-axis.
Normaly I expect the system is drawing enough power to keep the PC PSU away from shutting down due to no load.

Any hint what I can check to eliminate this issue ?

Regards
Pulmux

That tends to happen with ATX PSUs. They are designed to work with a significant load on the 5V output, which most RepRaps don't provide. The fix is to put a load on the 5V output, such as a 5 ohm resistor rated at more than 5W. A 12V 21W automobile stop light bulb would probably work too.

Or you can use a LED/CCTV PSU instead. They are available in both 12V and 24V, and generally have a pot to adjust the output voltage a little.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hm,

if the load is required on the 5v output, that would be my mistake than. I assumed there must be an overall load to the ATX PSU not specific to the 5V.
I will put some load to it next week.

Thanks for your info.