Heaters will not turn on

kvi94

@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.

kvi94

@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.

dc42

@kvi94 those pock marks look suspicious to me. I've Just examined three MB6HC boards, and on those boards I can read the figure 3 clearly at that location on the chip.

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.

kvi94

@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

@kvi94 yes you can use the VIN ground terminal, or the middle pin of any of the IO connectors.

kvi94

@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

kvi94

@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

kvi94

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

Thank you.

dc42

@kvi94 if you are sure that the heaters were on when you took the measurements and had not yet faulted, then it looks like those drivers have failed. Please email warranty@duet3d.com with a link to this thread.

kvi94

@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.