Duet maestro not connecting to DWC or being recognised by PC
-
Also if you have a meter, use it to measure the resistance between ground and 3.3v after taking the defective 3.3v regulator out of the equation. If there is still a short, then you'll need some serious repairs.
-
wow, 3,3 and gnd seem to be connected, i did a continuity test
-
3,3 supply doesnt work... instead it just gets shorted.
-
I'm sorry to hear of your misfortune. I think you have a short between one of the heater wires and the hot end metalwork, possibly inside the heater cartridge. Sadly this has caused VIN to be connected to +3.3V when your +3.3V wire touched the metalwork, which has caused components powered from +3.3V to fail.
Shorts between heater wires and the hot end metalwork are not uncommon, that's why we protect the thermistor connections against shorts to VIN.
If you are unlucky, multiple components will have failed and the board will be beyond repair. If you are lucky, only one or two components will have failed. The most likely to have failed are the SD card and the W5500 Ethernet chip. So remove the SD card, then apply USB power and see if the green 3.3V LED lights up. If it doesn't, check whether the W5500 or main processor or any other chips are getting hot.
-
i removed the sd card and the green led doesnt light up.
no other component gets hot.
the 3,3v regulator U2, i have cut the 3,3v pin to solder an external power source but when i measured between gnd and the pin, it was shorted and my external source got super hot, so i removed that. -
as soon as the vcc crimp of the sensor hit the hotend, the printer disconected.
the crimp didnt stay on the hotend, it just made contact for less a second and fell away from it. -
is there anything else i can try?
-
you pulled the sd card and no 3.3v light
you isolated the 3.3v regulator and supplied exeternal 3.3v and no 3.3v lightthat means you have a short in one of the other chips that need 3.3v; next step is to identify which ones get hot when you feed it 3.3v and remove one by one and when no more chips are getting hot and you get a 3.3v light start putting in new chips which requires smd rework tools to both remove and install.
which as i laid out before probably means you had a short to +12/24v and that causes more damage (than a short to ground; and you really want to find and isolate that short before repairing or replacing the Duet)
-
no other component gets hot... it was only the regulator, if the others dont get hot then how am i supposed to know which one i must remove?
I have no experience troubleshooting or fixing these boards nor do i have any smd rework tools.
can i send them to duet for repair?
because im not comfortable with removing and adding components, im afraid i might cause more damage than there is. -
@NEVER-LUCKY said in Duet maestro not connecting to DWC or being recognised by PC:
no other component gets hot... i
and you don't get a green 3.3v light if you apply externa 3.3v? its possible, but unlikely the led itself is damaged.
-
there is a short between 3,3 and gnd, the green led doesnt light up, when i apply voltage from usb and no other component gets hot.
-
If you have a short between 3.3v and ground, it would, unless using a current limtied supply, get warm when external power is applied.
And as i pointed out yesterday if you still have a short between 3.3v and ground after taking the 3.3v regulator out of the equation then at least some of the other parts will need replacing. The only reason to see which one gets warm would be to get an idea of the parts needed.
I'd take a look if anyone in this thread is near your location, or otherwise find someone with the skills and tools to assist you. there isn't much we can do online at this point.
https://forum.duet3d.com/topic/13875/community-repairs/ -
I will consider sending it to someone for repairs.
does duet themselves not repair boards? dont they have a repair service?
-
dc42 has said they do*, but as he implied it could quickly be beyond (economical) repair if the fault was caused by shorting 3.3v to Vin and that does sound like the most likely cause at this point.
the reason I started the other alternative is to avoid the boards to become landfill material as the largest cost is the labour and not the parts. doesn't matter to me if I spend an hour helping you on a forum or an hour repairing a board, if I have the time I'm happy to help the community either way.
*) with covid restrictions they might not be in office to such things for a while as well.
-
I understand your concern, but the problem here is that right now i have a lot of free time and i want to put it to good use to build out my custom printer, however this small accident ruined the entire board and i cant get anything done. Im not saying that i dont care about the environment and all, but i just need this board fixed so i can get up and running again.. and because i dont have the expertise to fix it, and now is not the best time to sent the board to other people in the community because of the situation we have in the world, i am comfortable with sending it back to duet.
Is there any way i can maybe get a replacement? -
@NEVER-LUCKY said in Duet maestro not connecting to DWC or being recognised by PC:
but i just need this board fixed so i can get up and running again
I'm not concerend; point is it could quickly end up costing more than a new board, and if we can't determine the extent of the damage you'll end up paying for finding out even its nor repaired. so the sensible thing is likely to buy a new one.
@NEVER-LUCKY said in Duet maestro not connecting to DWC or being recognised by PC:
Is there any way i can maybe get a replacement?
maaaaaybe, but its not for me to say; they have been known to offer refurbished boards at lower prices in such cases.
-
where should i request for one ?
-
I'd wait for them to offer you one tbh. (and if you look at their website, you might see it could take awhile but I'm kinda done repeating myself)
-
well alright.. ill wait.
should i do anything else or just wait here? -
@NEVER-LUCKY Sorry for your mishap, it’s an expensive lesson in a moment. If you email sales@duet3d.com with a link to this thread, and ask Roland if he has any refurbished Duets if you want to keep the cost down. I have no idea how long delivery will take in these uncertain times, tho.
Unfortunately this kind of damage is not covered by the warranty (see https://www.duet3d.com/warranty), and as @bearer points out it quickly gets more expensive to repair a board than buy a new one.
Ian
