MKS Base Reverse Polarity Repair





Introduction: MKS Base Reverse Polarity Repair

I was up all night, and decided at 5 am to fix my Printers input, because it had broken a few days ago. So I replaced the connector, but confused the polarity, yes I know, clever me, and I broke the board.

It wouldn't work from the power input, but it still would work from a USB, the motors wouldn't work of course.

My board was MKS Base V1.2

Sorry for the quality of the pictures, my phone has 5mp only with no manual focus and terrible autofocus.

Step 1: Step 1. Check the Fuse

Check with the continuity function of your multimeter across the F3 Fuse (near the power input)

If you have continuity continue to the next step.

otherwise replace the fuse.

Step 2: Step 2: Replace the Regulator

Disolder the regulator, clean the pads, and make sure you don't have any short circuit.

Solder a new regulator (L5970D) make sure you don't have any short circuits between the pins of the regulator.

PS: Be careful the resistors and capacitors next to the regulator so that you don't disolder them. I had to fiddle with R5, because I wasn't careful.



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2 Questions


Thanks for helping!

It's not F15, it's a fuse with the number 15 on it. I'm using the MKS Gen L and I messed it up by reversing the psu polarity. I was hoping the fuses would be similar in your board.


hi! I need to change the fuse labeled '15'. do you know its parameters?

Hi Lipigl, I can't find F15 could you send me a photo marking it?


Hi, I have a MKS GEN v.10 biqutreetech . after wrong polarity connection is dead... one diode burn.. i have change two diode but nothing.. one fuse ok but another no.. what is the valor of these fuse? 15 is 15A ??


MKS Base V1.1 - Does it look like I should replace the Fuse?
My multi-meter has no continuity setting; any idea what resistance should I be looking for over f3?


If it is a fuse, there should almost no resistance.

Sorry for taking so long to respond, I just logged in after almost a year

A fuse, it should have almost not existent, resistant, like a piece of wire.

Good info, thank you for sharing. And welcome to instructables!