Power Issues

I have the Duet 0.6, got it about two weeks ago from replikeo. I just finished building the frame for my new core-xy printer, and put in enough steppers to test basic movements.

When I connected the 24V PSU, the board would not turn on. I have 24V across the screw terminal with a multimeter, and the PSU lights up an LED strip just fine. I have 3.5V across the 5V rail. When my fingers brush against the pins (for instance when holding the board), the light briefly flashed red.

When the USB is connected, the board works perfectly. In fact, with the USB and PSU are connected at the same time, I can control the steppers I initially wanted to test (discovered I managed to connect them properly at least).

Any ideas on what's going on?

Assuming you are not using the external 5V linear regulator that Replikeo usually sells with their Duets, you need to enable the on-board switching regulator by putting a jumper across the 5V_EN pins (not the ATX_5V_EN pins). I recommend that you measure the voltage on the 5V rail after doing this, because I have a sneaking suspicion that Replikeo doesn't test the on-board regulator. You can measure the 5V rail between pins 1 and 2 of the expansion connector.

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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].

I am not using the 5V regulator they sell. I didn't order their "complete set."

Putting the jumper across the 5V_EN yields the same results as before, with the exception of a proper 5V (actually 4.8V, but nitpicking) now on the 5V rail. Besides there now being 5V, same symptoms.

Just to be sure, should I be putting a jumper across BOTH the ATX_5V_EN and 5V_EN pins, or just the 5V_EN? Right now I have it only one one or the other. On the reprappro duet commissioning page, there are instructions to only use the ATX_5V_EN jumper, so I am a little confused.

You only need a jumper across 5V_EN. See the reprappro docs for commissioning the Ormerod 1 or the Fisher. The Ormerod 2/Huxley/Mendel used the add-on 5V linear regulator board, because RepRapPro wanted to claim CE compliance in respect of EM emissions.

When you say that the board "would not turn on", what exactly do you mean? When a Duet 0.6 is powered just from the VIN terminal block, there is no LED on the board to indicate that power is applied (the Duet 0.8.5 is different, it has a different colour of LED for each power rail). The LED near the USB connector signals USB power. However, if you have normally closed endstop switches wired to any endstop inputs, then the endstop LEDs should be on except when the switches are triggered.

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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].

I couldn't get the ethernet port leds on or connect to Duet Web Control with just the PSU power, but they work with the USB power. I can't imagine this is normal behavior?

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Masterjuggler
I couldn't get the ethernet port leds on or connect to Duet Web Control with just the PSU power, but they work with the USB power. I can't imagine this is normal behavior?

No it's not normal behaviour. I suggest you check for the following voltages, with 12V power applied and USB not connected:

- 5V on pin 1 of the expansion connector

- 3.3V on pin 3 of the expansion connector

- 3.3V on any of the centre pins on the endstop connectors.

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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].

I found a 12V 400mA power brick (didn't feel like taking the PSU off my other printer) and hooked it up to the duet. Everything worked as it should. I then connected the 24V PSU and it's all working perfectly, with all motors and web control running, and all voltages correct.

I'm about to wire up the hotend and heated bed, and I have no reason to believe they won't work.

Thanks for the help.