Duet Wifi Dead ?
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Hello
this sounds not good
on the board is nothing what is hot. I think you mean the z endstop ? this is a mechanical micro switch. -
hi,
now i have controlled the Board Power on the 5 V i have 4.88V and on the 3.3 V i Have 3.1 Volts
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That's an odd failure mode. I've seen a couple of boards where the 5V or 3.3V rail appears to have been shorted to +12V or +24V, and in both cases the heaters turned on all the time AND some chips were getting hot (usually the 3.3V regulator, processor, and sometimes the 74HCT02 or 74HC125). If the 3.3V rail is only at 3.1V, that does suggest that the 3.3V rail is overloaded, in which case I would expect at least the 3.3V regulator to get hot.
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Today i have checked again all the kable in the hope to find a blank or lose connection which can cause a short circuit something must have happened but i can't find it.
The only part of the printer which are supplied with 24 V and 3.3V is the hot end but even there I found nothing I'm going crazy.I'm an electronics technician myself and this makes it twice bad that i can't find any error
At one point we agree that the board seems to be defective what may have ever happened is there a way to get this board repaired? if yes how? this board is 2 months old
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so far so good the printer works with a new Duet (except Y port) now is only the question what hav i to do to get the first board repaired ? can i send it directly or should i go to my German Seller?
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Today i have checked again all the kable in the hope to find a blank or lose connection which can cause a short circuit something must have happened but i can't find it.
The only part of the printer which are supplied with 24 V and 3.3V is the hot end but even there I found nothing I'm going crazy.I'm an electronics technician myself and this makes it twice bad that i can't find any error
It's not uncommon for the cartridge heater in a hot end to develop a short between the element and the case, sometimes only when is hot. This puts the entire hot end metalwork at +12V or +24V. So you only need a short from the metalwork to something else on the hot end assembly to feed +12V or +24V to somewhere that it shouldn't be. The thermistor connections on the Duet are protected against this, but not the 3.3V pin on the Z probe connector that provides power to the Z probe. What type of Z probe do you have, and is there any possibility that it could have shorted against the hot end metalwork?
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i don't use a z Probe i only have an Z-endstop switch.
here are some photos from the hotend : https://photos.app.goo.gl/GfxbeygkryZRTKCE2
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So is there any 3.3V wiring on the hot end apart from the thermistor wires?
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Looks like a large DSUB connector, perhaps a stray wire inside that connector shorted +24v to +3.3v?
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on the first photo you see a gray flat cable this is the only 3.3V to the optical x endstop This cable goes directly to the Duet the other cable (fan/hotend and Thermistor) goes to the sub D connector and then to the Duet.
All used pins in The sub D case are isolated with shrinking tube -
Please put in a warranty claim to your supplier.
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ok Thank You i will contact my supplier
