Duet wifi board bed heater not switching off

Veti

please post some high resolution pictures of the board to see if any components have failed. specially u3.

Modelman

Hi Veti

I have attached 2 photos 1: U3 and 2: showing LEDs

T3P3Tony

hi @Modelman We do ask resellers to direct customers with issues that are not definitely hardware problems to the forum so we can check what the problem is. If its a hardware issue under warranty then of course it will be covered.

In this case the diag on all the time may be due to firmware being erased however the bed LED should not be always on so there is a hardware issue.

May I ask how the bed was powered? Did this happen the first time you used?

droftarts

@Modelman said in Duet wifi board bed heater not switching off:

@Veti I am a bit annoyed because I purchased a genuine Duet wi fi board thinking it would carry a warranty unlike the cheap cloned versions I could buy from China. Apparently not Ooznest have directed me to this forum and also Duet will not proceed a warranty claim because I purchased it from a reseller.

You have a warrant; please see our warranty policy here: https://www.duet3d.com/warranty

As you will see, the first step is to confirm if this is a warranty issue, by posting on this forum. If we determine it is a warranty issue, you then contact the reseller to proceed with the warranty claim, using this thread as authorisation.

Was the board fitted to your printer? Had it been working, or was this the first time you had set the bed to heat up? From the look of it, I suspect the bed MOSFET has failed, but it would be good to check that this wasn't due to faulty wiring.

Is the USB lead you are using the one that was supplied with the Duet? A lot of USB leads are for charging only, and don't have the wires to actually communicate too. Please try a different USB lead, one that you are sure that works for data as well as power. If the diag LED is on, the firmware has been erased. Please follow the steps here and report back what works/doesn't work: https://duet3d.dozuki.com/Wiki/What_to_do_if_your_Duet_won't_respond

Ian

Modelman

@T3P3Tony
I had the board powered from my Wanhao psu 24v and using the 5v EN configuration. It has been working fine until this morning when I noticed the bed was getting extremely hot and I tried to shut the heater down usingI thought by resetting the board it would be okay but finished up with the diagnosis LED permanently on.

T3P3Tony

@Modelman its not possible to say from this report why the fault occurred so please ask ooznest to replace the board under warranty with this thread as the authorisation.

Please triple check all your wiring (not just the bed wiring) before pluggings in your replacement board as this sort of failure can be caused by 24V being applied to 5V or 3.3V which can happen if the is a break between two wires or similar issue.

Modelman

@droftarts
I have been using the same USB lead that I have used with my Serial Tools and BOSSA to initially connect to my computer (iMac) and it has been working fine. I have had the board connected to my printer and had just got the IR probe configured and working. I had done some test prints using PETG but was getting bed adhesion problems, so was trying different adhesives on the bed. I did a complete install of the Duet Combined firmware using BOSSA and verified ok but the diagnosis LED will not go out and the heater LED remains dimly lit.

Modelman

@T3P3Tony
Initially I wanted to purchase the board from Duet direct but was directed to a reseller. If I get this sorted out I am thinking of buying another for my Anet printer. I will try again to purchase from Duet direct because of their warranty policy, that I did not know of at the time of purchase. Otherwise it would have to be a clone from China and lose £70 and not £144.

T3P3Tony

@Modelman our warranty policy applies equally to boards purchased from us and from our genuine resellers so feel free to purchase another from ooznest!

As i mentioned above, this thread is sufficient for them to action the warranty.

Modelman

@T3P3Tony
Thanks Tony, I have just had an email from Ooznest and they have instructed me to send package details for the to arrange collection. I am very impressed with the Duet board but have found the set up instructions a mine field because they cover a selection of boards. I have been viewing this forum for setup info along with YouTube. I had a problem with trying to use my IR probe to home Z because I was using an optical end stop as well. There was another guy had the same problem and it was pointed out he was using an end stop as well. There was no resolve. I did this and it works fine: M574 Z1 S2 ; set Z limit switch

Z-Probe
M558 P1 Z1 C"zprobe.in" H5 F200 T5000 R0 ;set Z probe type to switch and the dive

Phaedrux

@Modelman said in Duet wifi board bed heater not switching off:

I had a problem with trying to use my IR probe to home Z because I was using an optical end stop as well.

You can use both or either. It all depends on how you call for the homing to happen. Both an endstop and a probe can be configured for the Z axis at the same time. Endstop with M574 and probe with M558. In the homing files, G1 H1 moves will call the endstop into action. G30 will use the probe.

Modelman

@Phaedrux I forgot to say that I removed the optical Z stop and just used the IR sensor. I found that if I used the optical end stop and Z probe I was getting a large Z offset on my mesh map. I could reduce the offset by adjusting the height of my optical Z stop. Now I use the mesh map as reference to adjust my bed manually and once level I then adjust my Z probe offset in my config.g.

Phaedrux

@Modelman You can still use an endstop for homing if you wish but the probe still must be used to establish Z0 with G30 before creating or loading a mesh to prevent the offset.

Modelman

@Phaedrux
To establish Z0 I have been pre-heating then home all axis and then posn. nozzle at bed centre. I then inched my Z down to 0.1mm from bed and then reset Z=0. I then raised the nozzle 5mm and deployed my IR probe. I read the resultant Z offset and put this figure into my z probe offset in config.g. I then performed a mesh compensation action. After as a check I again positioned my nozzle at the bed centre and jogged down until Z = 0 and checked nozzle bed clearance. It has never been 0.1 as set, so I have to adjust the z offset to get my desired 0.1. I think the probe is reflecting off the glass bed bottom face, I have tried using black paper as a backing but my glass bed slides about on it. So I have used heat sink double sided tape and set my mesh grid to probe 4 corners. I also discovered that any mechanical clearance in my hot end linear bearings etc can influence the IR probe results. I have reduced any play in my hot end transport and things are now much better. I will try G30 as you suggest. I was a total newbie to configuring G code . My knowledge was limited to start and end code in Marlin for slicing.

Phaedrux

This may be helpful then.

https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe