RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
All step-down-modules I've ever used could be adjusted without a load. The voltage with an actual load will be slightly lower (11.7V instead of 12.0V in my case), but an unchanging output of 0.2V doesn't look healthy to me.
It won't hurt to short the output using somethink like a 10kOhm resistor to check if it helps, but I would assume that a broken module is a more plausible explanation.
RE:
I recently ordered a parts kit for building a Nevermore Mini filter. The kit came with a step up module for 5 V to 12 V. When I wired it for testing according to the labelling for input and output, my multimeter always showed 0.7V on the output. Reversing input and output gave me always 12 V output on the terminals labelled "input" with varying voltages on the terminals labelled "output". Just another possibility for parts made in China. 🙂
Although that one was without a potentiometer.
RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
Well I plugged in the noctua 12v - fan didn't start and the load "dropped" to 0.16V
RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
I would not start with the fan, that could damage it if the voltage is too high. I would use a cheap resistor for the load, like Zappes said.
RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
Yeah I'd have to have said resistor 😀
I can put two 12v fans in series and plug into 24v that could work too. I asked some friends around if they have something that could help but need to wait till the evening.
RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
And if one of the fans fails for some reason the other one gets grilled. I would not recommend it.
I meant using the resistor for testing the step down module.
You can also use a properly sized resistor to just "burn" 12V. You can find a formula for calculating the resistor value here: https://maker.pro/forums/threads/running-a-12v-5a-fan-from-24v-6-5a-source.269485/
RE:
I took that board to my buddy and under a soldering "microscope" we saw a tiny particle of metal wedged between two pins of the main processor. Maybe that was my mistake, maybe that was production fault. Could not revive that board but fortunately for me, my buddy had different one, so we put everything together and et voila.
I am now printing for 40min with petg, doors closed again and the MCU reports 54C (board and bed still report "not initialized", that sometimes initializes at some point). Bed is set to 90.
I left the potentiometer accessible (although need to take whole thing out of the board) and undervolted the fan (reduced vibrations/resonating) and still 54C is a great improvement.
A note on the model - I printed in PETG and it could have been thicker - its too flexible for my taste but works perfectly fine.
Kudos to both of you for your ideas!
RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
Do you have the design please ?
RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
You mean for the cover with the fan? Here you go: https://www.printables.com/model/580484-cover-for-adding-an-80-mm-noctua-fan-to-the-mk4-el
RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
Thank you !!
RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
Does anyone know the size of the chip on the mainboard to install some heatsink ? thanks
RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
I posted a photo of the heatsinks I installed on my board which can be found under the link for the cover a few posts above. Sizes for the heatsinks are also part of the description text there. I do not think that you need a heatsink on the big CPU chip, just on the TMC stepper drivers and the MosFet for the heated bed. These are the chips that will get really hot, because they have thermal pads on the bottom of the board. The CPU (the big square chip in the middle) does not have a thermal pad on the back.
RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
Well i have an actively heated enclosure, i just wanna be safe. I have a 300W ptc heater
RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
I have the 2 24 volt fans wired in parallel. This is my setup. I just added a 40C, NO, normally open thermal switch to the top of the buddy board case. See attached picture. It is attached with thermal glue. When the board is about 55C, the fans come on and drops it to around 45C while printing. Fans turn on well below any board overheat temperature. Tip, use a hairdryer to heat the case to get the Thermal Glue to set quickly, just needs to get warm.
A 45C or 50C switch may be better. The 40C will not turn off until it gets to 30C, which is often too warm to turn off after printing when the printer is idle. Check the switch specifications.
RE: Possible overheating of the MK4 electronics case inside an enclosure with summer temperatures?
Just perfect. Problem experienced first time...because of hot weather....and solved in 2 days (with delivery of the cooler fans)
Thank you Guys, especially @walter-layher Walter! 😀