Here's one of my builds:
On the mainboard side, be sure to use a soldering iron with at least 50W, especially on the "ground" side, the heat is dissipated across a large area, so you want to be able to heat the soldering point in a few seconds.
For those who wonder, there is a fuse, it is the black round dot on the upper left corner of the PSU, so there was no need to add another, discrete one. An R/C filter is also already part of the PSU. Grounding is done over one of the screws that fixes the mainboard to the enclosure.
I glued 3 small epoxy-board squares on the enclosure (arsenic-based instand glue, so they would never ever come off), then I pre-drilled the holes (2,5mm) and used self-drilling 3mm screws to fix the board, ensuring enough clearance on both top and bottom of the enclosure.
I used a salvaged 24V, 1A PSU. This one is open frame, so it is absolutely essential to put a sticker on the enclosure stating that there are no user-serviceable parts inside, and that there is a risk of potential electric shock, possibly lethal!
I did not cover up the input jack because I use it as a power output to feed another device (check the total power consumption, it shall not exceed the power supply's capacity!
Disclaimer: This is potentially lethal, so I explicitly discourage you from building it on your own, unless you really know what you are doing and take full responsibility for that! There is a reason why Mikrorik did not sell this device with an onboard PSU! I am not responsible for any damage, including, but not limited to, injuries and/or death!
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