UPDATE

I managed to get my hands on a miniature pcb relay. The fans are now powered by the PSU and duet3 24V always-on activates the relay coil.

It is working as intended now, M999 does not turn off the board.

I am guessing that power drawn from the 24V always-on should not exceed 100mA, as for now I have around 40mA connected.

Thank you everyone for your inputs

@dc42 I had someone to keep an eye on DWC for any fault while I took the measurements, so I am pretty confident they had not faulted.

@dc42 said in Heaters will not turn on:

Please email warranty@duet3d.com with a link to this thread.

Alright, I will get this done.

Thank you.

@dc42 did you manage to take a look at the values? What does it suggest?

Thank you.

@dc42 I managed to measure the voltage when the heaters are in active state by the firmware, the reading are as follows:

R40 = 0.001V
R115 = 0.025V

R53 = 0.585V
R57 = 0.004V

@dc42 Please find below the voltage of the resistors when both output are off.

R40 = 0.001V
R115 = 0.025V

R53 = 0.032V
R57 = 0.001V

@dc42 said in Heaters will not turn on:

To measure the voltage that the driver is feeding to the mosfet, measure between one end of the mosfet gate resistor (e.g. R115) and ground.

@dc42 As I will be doing this while it is powered via USB, using the input GND terminal is fine? Additionally, should I set the port active with a temperature and measure or measure at idle?

@dc42 please take a look at the close up pictures of the 74HCT365 chip. Can this be the cause for the fault?

Could you please guide me where to place the test leads to measure voltage for R115, R40, R53 and R57. I posted location pictures for the components in my previous post.

Thank you.

@phaedrux Thanks for pointing this out, I guess it comes with experience. I just had a look at it, there is something but I cannot say if it is a pock mark or a bulged. I will take a look at it tomorrow under daylight and post pictures.

Thank you.

@dc42 please find below pictures for R115, R40 and R57. Is R53 located next to temp3 pin by chance?

I have put 3 coloured dots on the mosfet pins for R115 and R40, if you do not mind could you please tell me explicitly where to measure the required voltage. It is my first time doing this at this scale, I really do not want to mess up things since this situation is already stressing me out.

Regarding R57, should I measure across the 2 terminals of the resistor itself?

Thank you.

R115

R40

R57

@dc42 please find below the output for M950 and M307 commands

M950 H0
Heater 0 pin out0 frequency 250Hz, sensor 0

M307 H0
Heater 0 model: heating rate 0.593, cooling time constant 389.7, dead time 3.93, max PWM 1.00, calibration voltage 0.0, mode PID
Computed PID parameters: setpoint change: P76.6, I1.957, D210.7, load change: P76.6, I5.418, D210.7

M950 H1
Heater 1 pin out1 frequency 250Hz, sensor 1

M307 H1
Heater 1 model: heating rate 1.680, cooling time constant 233.0/193.0, dead time 6.75, max PWM 1.00, calibration voltage 23.7, mode PID
Computed PID parameters: setpoint change: P15.7, I0.397, D74.4, load change: P15.7, I0.865, D74.4

The PID parameters are the same as in my config.g for H0 and H1.

Below is output for M98

M98 P"config.g"
HTTP is enabled on port 80
FTP is disabled
TELNET is disabled

@dc42 sure, I will locate the resistors and confirm with you in a while.

Thank you.