Damaged capacitor
Hi everyone,
when I tried to install the official filter in my Core One, I unfortunately noticed that a capacitor had broken off (C147 on xBuddy board). Is this a manufacturing defect, or did I damage it when opening the cover? (For example, by tilting the cover incorrectly?)
Unfortunately, the clarification process with my supplier is taking a very long time. Does anyone know if the printer might also work without this capacitor (it worked without any problems before opening it)?
RE: Damaged capacitor
Looking at the schematic: https://www.prusa3d.com/downloads/Electronics_drawings/FDM-xBUDDY-44.pdf, it appears that this provides low pass / smoothing filtering of the bed heater voltage prior to it being digitized for monitoring. With it out of the circuit I would expect errors on heater voltage sensing as it will be a noisy / seemingly erratic signal. I am sure the driver for the heatbed is switching on and off as it maintains temp and this would be a significant source of electrical noise.
I would replace it with a generic 100uf 35-50v capacitor. You could do it "dead bug" style if you can't do the surface mount soldering. Flip the new cap upside down, use a dab of glue to hole it next to the terminal block and run the leads to the old connections and solder them carefully in. Don't leave the leads overly long. Be sure to get the polarity right or it could potentially explode eventually.
Based on the dent in the side of the capacitor, on the side it is pried up, it sure looks like it was whacked by something.
Don't stress the remaining connection - you need to avoid lifting/tearing the track or the repair gets much harder. If the position is hard to reach to de-solder it might be worth cutting the remaining lead (side cutters).
As @bronk says, the polarity matters. His idea of gluing the replacement close by is sound as those solder pads must now be fragile - if you are not confident in conventional soldering the expensive but much easier way is to use solder paste - bend the leads into position then squirt solder paste into the joint - you can prod it into place with a small screwdriver if necessary, finally touch the paste with a hot soldering iron to complete the connection.
Cheerio,
RE: Damaged capacitor
>> Does anyone know if the printer might also work without this capacitor (it worked without any problems before opening it)?
Let me put it carefully: If I had noticed the defect by accident and the printer works fine, I would have no objections using it as is. The PSU on the other end should have adequate filtering.
But don't sue me if your printer collapses into a black hole and swallows the earth.
RE: Damaged capacitor
I just can't imagine how I could have damaged this capacitor simply by opening the box, so I'm still hoping the entire board will be replaced under warranty. (However, I've been waiting for a response from the supplier for four weeks now.)
The only capacitor I have is a Panasonic electrolytic capacitor, 1000 µF 35 V 10 mm x 25.0 mm, which I just happened to have at home from my model railway.
Would those work?
RE: Damaged capacitor
It would be hard to hit that cap by opening the box. It looks more like somebody slipped while doing something with the heavy wire connection just above it. I wouldn't use the 1000 uF as it's so much larger. Try to find something closer to the original value.
RE: Damaged capacitor
But the question is, what is that?
For the capacitor, you can find one on an older, broken electronic board, such as a TV or similar device. It is easy to replace using a standard soldering iron, as long as the tip is not too thick.