My CR filter stopped working a couple months ago, and I suspected it may have been the PWM controller (which is the only active piece of electronics in the thing). At the time, I tested the fuse (for continuity) and it was good, and then decided I'd order a spare PWM controller to have on hand and then get back to fix it "sometime". Well "sometime" was today. I first rechecked the fuse (again for continuity), and then proceeded to disconnect the controller. and found it was reading 13v at the input (as it should), but only 4.2v on the output (which was strange). 4.2v is not enough to turn the fans over, but it was enough to glitch the LED ring when I turned the PWM controller on. The controller also had a red activity LED when turned on (which was correct for these). Next I decided to check the resistance in the power lines, which run from the DC inlet, through a fuseholder, and then up to the PWM controller. The meter read almost no resistance on the positive but had 14 Ohms on the negative (so I was starting to get somewhere). Unique to the negative line is the fuseholder, so I tested resistance from the terminals of the holder back to the PWM controller, and it was low as it should be. And then I got the bright idea to check the resistance on the fuse, which was... 14 mother-trucking Ohms. If it had just blown, the problem would'a been solved months ago, but it somehow just decided to get all difficult (for electrons to pass through).
Swapping the fuse fixed the problem, but unfortunately for me, I cut a few of the wires during the "troubleshooting", and had to re-solder them up before I buttoned the whole thing back up. I'm sorry I doubted the little PWM controller too, it was running like a champ, just like the one I put in my Bento Box clone filter (which has been running for well over a year off and on when I run prints). Troubleshooting things did give me a few ideas to make it much easier to work on though, which would be implemented in any future designs for these types of filters.
I also discovered that the filter was definitely working, since the inside was dusty as heck (I stupidly set it up to pull dirty air in and exhaust clean air, vs the opposite - and smarter way of setting these filters up).
I had thought the CR filter project was sort'a a bust, but now I'm reconsidering if it may actually be a success given how much dust was apparently stuck in the filters. I guess every cloud of dust has a silver lining.
Swapping the fuse fixed the problem, but unfortunately for me, I cut a few of the wires during the "troubleshooting", and had to re-solder them up before I buttoned the whole thing back up. I'm sorry I doubted the little PWM controller too, it was running like a champ, just like the one I put in my Bento Box clone filter (which has been running for well over a year off and on when I run prints). Troubleshooting things did give me a few ideas to make it much easier to work on though, which would be implemented in any future designs for these types of filters.
I also discovered that the filter was definitely working, since the inside was dusty as heck (I stupidly set it up to pull dirty air in and exhaust clean air, vs the opposite - and smarter way of setting these filters up).
I had thought the CR filter project was sort'a a bust, but now I'm reconsidering if it may actually be a success given how much dust was apparently stuck in the filters. I guess every cloud of dust has a silver lining.
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