Unusual dual part cooling fan failure
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Just thought I'd share this in case it helps others in the future.
I have two small blower fans connected in parallel as my part cooling solution. The printer has been idle for a few weeks but I turned it on today and noticed that both fans had stopped working. I connected a spare fan to the Duet board and this worked fine. At this point, my thinking was that there had to be a fault in the wiring between the board connector and where the wiring splits into two to go to each fan. I checked the continuity between the board connector and that junction point which was good. But when I measured the voltage at that junction, it was showing only about 1 volt (with the demand set to 100%) whereas at the connector, it was 12V.
To cut a long story short, I disconnected each fan in turn. With only the right hand fan connected, the voltage at the "Y" junction was showing 1V and the fan did not turn. The fan itself turns freely by hand and is not seized. With only the left hand fan connected, the voltage was 12V and that fan worked fine. With both fans connected, the voltage drops to1V and neither fan turns.
So there is a fault on the right hand fan which must be an "almost short to ground" which prevents both fans from turning when two are connected together. This has not damaged the board or blown any fuse.
I just thought that it's an unusual failure so worthy of mention..............
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@deckingman said in Unusual dual part cooling fan failure:
I just thought that it's an unusual failure so worthy of mention..............
For me the real headline is:
@deckingman said in Unusual dual part cooling fan failure:
The printer has been idle for a few weeks but I turned it on today
'A few weeks' is a mild understatement from what I know, so I'm glad your interest in 3D printing isn't entirely gone...
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@o_lampe said in Unusual dual part cooling fan failure:
For me the real headline is:
@deckingman said in Unusual dual part cooling fan failure:
The printer has been idle for a few weeks but I turned it on today
'A few weeks' is a mild understatement from what I know, so I'm glad your interest in 3D printing isn't entirely gone...
You mean what you think you know. You didn't spot the clue I left when I changed my profile picture a couple of days ago