Curious about a missing capacitor

AlexMl

Hi,

I received my Duet Wifi 1.04c and realized that there is no capacitor soldered onto C99. All pictures that I found on the web show a capacitor at this spot and I didn't read of any change, so I want to make sure that the circuit is ok before I disassemble my working printer.

Can anyone please confirm whether this is by intention or should I file an RMA?

Thanks and best regards,

Alex

DocTrucker

@AlexMl appears to be one of the capacitors after U3. U3 is responsible for providing 5VDC from V_IN.

https://github.com/T3P3/Duet

Wait for the Duet team to comment on it's presence. I can't see where the notes are for the changes on hardware revisions.

dc42

C99 has been omitted intentionally in the most recent Duet WiFi production.

AlexMl

Thank you very much @DocTrucker and @dc42 ! Looking forward to install the board!

themelle

@dc42 said in Curious about a missing capacitor:

C99 has been omitted intentionally in the most recent Duet WiFi production.

Is this a self-contained change - so users of older 1.04 boards may also just remove C99? Or is it part of a bigger rework with multiple dependent changes?

dc42

It's a self-contained change. But there is no need to remove it if your Duet is working properly.

themelle

@dc42 said in Curious about a missing capacitor:

It's a self-contained change. But there is no need to remove it if your Duet is working properly.

Thanks a bunch, David!

DocTrucker

@dc42 said in Curious about a missing capacitor:

C99 has been omitted intentionally in the most recent Duet WiFi production.

1.04b pdf? Is there a readable list of changes any where to save us needing to ask about changes or play spot the difference when pdfs are available?

T3P3Tony

@DocTrucker I have uploaded the pdfs here:

https://github.com/T3P3/Duet/tree/master/Duet2/Duet2v1.04

The version history explains the overview of the changes:

https://duet3d.dozuki.com/Wiki/Hardware_Overview

We don't publish a list of everything component moved/added/changed/set to DNP etc.

droftarts

Particularly as C99 is near the 5V regulator, I expect it's related to this:
"Further minor component value change/tweaks to improve 5V regulator and EMI performance."
https://duet3d.dozuki.com/Wiki/Hardware_Overview#Section_PCB_revision_v1_04a_b_c

Ian

DocTrucker

@T3P3Tony thanks, the combination of schematics and readable over view is plently.

@droftarts yes, I suspected something along those lines as it was on the output of U3. Tony added the readable comments at the same time as the pdfs:

https://duet3d.dozuki.com/Wiki/History/Hardware_Overview?revidA=2007&revidB=2367