Monoprice Select Mini V2 – Power Switch Replacement

Owning a Monoprice Select Mini V2 is a sure way of getting you on forums where people try to fix various problems with the printer.

I had two major problems with the printer so far:

  • Very loud fans after maybe 10-20 hours of printing. Swapped them with Noctua fans.
  • Loose Z-Axis gantry nut which fell onto the coupler. Had to take the printer apart to see what’s going on inside and decided to super-glue it back onto the gantry paying attention not to glue the threaded Z-Axis rod.

One of the things I found out about on the said forums is that that some people reported problems with the power switch, which seems to fail after a while. Mine was OK, but, given the gravity of the situation in case it did, I decided to swap it anyway.

For example:

Trouble is that most advice given suggest fixing it with switches with similar “quality”. Either buying a spare one from the official website, or buy similar ones that are so cheap they have to be sold in bulk. Won’t this fail the same way ?

Wanting to reduce the risks (some grave) of using the machine – I decided to replace the button with one that fits but is sold by a reputable electronics seller.

First trouble … which size does it have to be ? Since I figured I should not take it out until the spare part arrives.

The official website doesn’t seem to list the part number of the power switch, I found that the original power switch is a KCD1-101 and following this, that the size of the button is 18.4mm x 12.6mm according to https://www.cytron.io/p-2-pin-kcd1-101-rocker-switch-6a-250v-red.

Second trouble is … none of the sellers are providing the DC rating of the switch! All the sellers rate the switch as 6A @ 250V AC, but none mention the DC rating. The printer can provide 7A at 12V DC, so I had to find a suitable replacement.

After browsing for a while, ended up choosing KRE2ANA1BBD: https://be.farnell.com/zf-electronics/kre2ana1bbd/commutateur-bascule-spst-16a-125v/dp/2787227. It is rated 16A for 14VDC which should provide plenty of headroom vs the 7A the power brick can supply, and has the same dimensions as the original.

Ordered and installed it – I needed a small screw driver to gently pry off the spade connectors – they were very well attached.

I have to say the new one is much smoother to operate and quieter:


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