Damaged board
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I just setup a duet 5 and when I powered it on and blew a fuse. I replaced the fuse and checked connections. I repowered it and it seems to have melted the drivers.
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@exzile wow. What motors did you have plugged in?
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@t3p3tony the nema16 I believe. I did get a new PSU and maybe I had the polarity backwards? Or both ++? The new PSU has the labels shifted I noticed. I removed all the wires and rewired it after the fuse blew to prevent any damage. But I think it may have been to late
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I was figuring the board might be defective but then again it could be the PSU. I'm afraid to hook it into my old board to try.
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@exzile said in Damaged board:
I did get a new PSU and maybe I had the polarity backwards?
Oh man, that's going to blow you board up.
This is the thing I worry about most when hooking up a new system and I
- ALWAYS leave the power supply connections for last and
- ALWAYS check them with a voltmeter right at the wires I'm about to hook to my new board to verify the polarity and voltage is correct.
I still sometime hook things up backwards and blow them up.
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@exzile yes that does look like reverse polarity killed it. That form of miswiring is not covered by the warranty.
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@exzile another case of "buy a good known brand psu"...I'm only using meanwell psu...it coast a bit more than chinese stuff but then again you get what you pay I guess, and always check the output
with multimeter to be 100% sure... -
@weed2all said in Damaged board:
@exzile.............. another case of "buy a good known brand psu"...I'm only using meanwell psu...it coast a bit more than chinese stuff ........................
Whilst I agree with the sentiment, and use Meanwell PSUs myself, unfortunately if you bought a genuine Meanwell PSU, the chances are high that it was in fact made in China. Their production bases are in Taipie (technically that's in Taiwan but the Chinese Communist Party say that is part of China), Huadu district in Ghanzhou, and Suzhou City in China. Although since 2019 they do have another production base in Bangalore, so it might have been made in India rather than China.
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@deckingman, China is quite capable of producing quality components so the actual location where something is produced is not that significant. The problem arises when a clone manufacturer decides to use cheaper components or processes to increase the profit margin.
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@jens55 you're right that chinese stuff can be good...but the problem with the clones is exactly what you said...it uses cheap components to achieve lower prices...as I said is preferably to get a good known brand psu in this case for a few $ more and never have issues than to cut corners and buy cheap no brand no name psu...
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@deckingman it doesn't even matter much where it is made either in China or India or Vietnam because is made under a name/brand and use good quality components and the QC is also way better...
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@weed2all .... yup, I also only use Meanwell power supplies. I also only buy these from reputable sources (not Amazon or Ebay) because there are way more clones out there than a person would think .... and they are extremely difficult to differentiate from the real thing.
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@exzile said in Damaged board:
The new PSU has the labels shifted I noticed.
Yes, that looks odd, as if you connected to two COMs. Can be dangerous it causes you to shift the mains inputs. I wouldn't expect this from a meanwell.
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@weed2all We are in agreement. In fact the opening sentence of my post said exactly that. I was just pointing out that as something like 30% of all manufactured goods originate from China, it would be difficult to find anything which does not originate or at least contain some components which originate from China.
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@deckingman ohh right...though that you stated it is not good if made in china...it was 1am here when I read your post
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Getting back to the main topic, whether or not a Duet will survive reverse polarity input depends on the power supply. The stepper driver output mosfet body diodes are forward biased, so they will conduct the current and clamp the voltage to about 2V because there are two in series. A good power supply will go into hiccup mode when it sees this near short-circuit, which means it will supply short bursts of its maximum current or a little greater, with longer intervals of no current. I have known Duets survive this, with no blown drivers and the fuse remaining intact. A less good power supply may just supply its maximum current continuously.
Duet WiFi hardware designer and firmware engineer
Please do not ask me for Duet support via PM or email, use the forum
http://www.escher3d.com, https://miscsolutions.wordpress.com -
@dc42 well in this case didn't survive as a use of cheap clone psu!
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I avoid Chinese power supplies not because it can damage my duet but because it can damage me, my family, and our home.
If Meanwell (Taiwan) or other reputable manufacturers choose to manufacture in China, but own the process, spec, and certification it's fine with me.
Edit: for high quality Meanwell PSUs, I recommend the UHP series. They are compact, highly efficient, stay cool, and are fanless.
