Mistery smoke on 6HC
DDD last edited by DDD
Something odd happened to my Duet 6HC v1.0 WD31943 + 3HC hook up with a RPi4.
I was trying to read a sensor connected at the 3HC.out4 using M409 command. Suddenly, a smoke came off from the L4 component on 6HC in the picture. After turning everything off and looking for errors, 6HC works fine like nothing happened.
What function does this component have? Where should I expect an error to occur?
I repeat, there seems to be no issues with 6HC
A Former User last edited by
Guessing its a filter for the internal 5v supply
how's the power arrangement for the pi?
Looks like the 5V output was overloaded. It turned out that the overload protection of the 5V regulator that we use on the MB6HC isn't very good. The rated current of the regulator is 3.5A but the overload protection may not kick in until 6.5A. L4 is the component that fails or smokes first when excessive current is drawn from 5V.
On the version 1.1 boards, we beefed up L4 and added a 3A PTC fuse.
I suspect that you were powering too much from the 5v rail, for example a RPi 4B plus HDMI screen. Or perhaps you had a transient short circuit between +5V and ground.
A Former User last edited by A Former User
@dc42 looking at the jumpers it looks the
DuetPi is externally powered? thats why I asked OP to confirm.
DDD last edited by
The RPi was powered externally using a 5V power supply
There is a high chance that I made a short circuit on the IO_n port. "Duet" to my jump scare everything was unplugged as soon as the smoke appeared before made a thorough inspection. My bad
Everything works normally. What problems should I expect if L4 fails completely?
I think it's unlikely that L4 will fail unless you get another short circuit, but if it does then the internal 5V regulator will just stop working.
DDD last edited by
@dc42 I'll keep an eye on it and try my best not to definitely fry my board this time
Really happy with how you design this board. It has been a blast playing with them.
Kudos to you and the Duet team!