Duet 3 6HC Output_0 always on

tpyoknig

@razrudy I don't think this is config related as replacing my config with a default one, or not one at all the same behavior exists.

@fcwilt I don't know. Could that be related to the fuse that I replaced that was loose at the start that was causing the bed to power on and off randomly? Or something else?

razrudy

@fcwilt said in Duet 3 6HC Output_0 always on:

@razrudy said in Duet 3 6HC Output_0 always on:

Also the OUT_0 output is controlling a mosfet ( that's the reason for that "thick" wires on output )
I also have separate PSU for the bed controlled by the mosfet.

Why is the OUT_0 output controlling a MOSFET?

Frederick

Separate PSU for bed. Is there any other way to control the mosfet?

fcwilt

@razrudy said in Duet 3 6HC Output_0 always on:

Separate PSU for bed. Is there any other way to control the mosfet?

The 6HC has the separate power input for OUT 0. If the current rating of OUT 0 is adequate you can connect the bed power supply to OUT 0 POWER IN and the bed directly to OUT 0.

Just verify that the grounds of both power supplies are connected together if the two board ground connections are not.

Frederick

tpyoknig

I've tried this with seperate supplies, the same supply and new power supplies to no change in the problem I'm experiencing so I don't think it's related to the power suppl(y/ies).

razrudy

@fcwilt 1000W 40A PSU too much for the board

@tpyoknig I am inclined to believe that most likely the mosfet on the board is the culprit for your problem

From dozuki manual :
"The ground side of OUT_0 is switched by the mosfet and the positive side is protected by a 15A fuse."

tpyoknig

@razrudy That was my conclusion as well but per Filastruder I have to have a mod/admin approve to get an RMA issued.

fcwilt

@razrudy said in Duet 3 6HC Output_0 always on:

@fcwilt 1000W 40A PSU too much for the board

Your bed heater draws 40 amps?

Wow.

Frederick

Phaedrux

It would appear that the mosfet for Out_0 has failed closed. Not a good situation. Please contact your vendor and initiate a warranty exchange and include a link to this thread as authorization.

razrudy

Can you see any damage or something on the mosfet on the board? Maybe one "leg" is not soldered properly

tpyoknig

@Phaedrux thank you - I've linked them to this thread.

@razrudy the mosfet looks fine. No physical damage, bulges, loose connections etc.