OLD PSU wiring diagram

Hello Bought a used K40 and it has a old PSU I would like to upgrade the PSU but a wiring diagram would help out a ton and a link for a $$ friendly PSU that will work on my k40

If someone has the diagram or has replaced this PSU please help if you can

Thank you,

It’s likely we can help.

Need a picture of the connectors on:

  • The LPS (picture 3)
  • The supply on the wall showing the labeling on the front edge (picture 1& 2)
  • The controller and its connectors and labels

Other pictures:

  • The control panel front
  • Control panel back

What is that metal can in lower part of picture 3

From this we can create a wiring diagram for you.
We can also choose a new LPS.

So I know how to prepare this info:

  • What is your electronics and wiring skill level.
  • Do you have a DVM and know how to use it.

Here is a what I captured years ago on stock wiring:

There is more info & details of the K40 in this blog FYI.


We might be looking at one of the earliest K40/K50 lasers. The name on that left wall mounted board is LCShenhui and they don’t exist any more but a few forums ask about them back in 2010.

I’ve looked at this pics a bunch and best I can come up with is that they had separate HV PS and LV PS and what we see is the LV PS transformer at the bottom of pic #3 and the board on the left wall is a 24V/5V power supply. As you mentioned, a few more pics and info might show how things are wired thus exposing what they do.

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Sorry for posting so many times but for some reason it wouldn’t let me post all of the photos in on post

My visceral advice is:

Trace and draw all the current wiring to and from each subsystem, include wire colors any signal names, etc.

We can use this to create a new wiring diagram with new LPS.

We need to see and decide if the control panel will meet your needs.
We need to see and decide what controller you will use.

----- Observations ------

Looks like the green terminal block is AC distribution.

The metal can is actually a transformer, perhaps for a linear LV supply. But its output does not seem to go the sidewall mounted supply.

The LPS inputs are not labeled on board.

The green thing is a ballast resistor that is not needed with a new supply.

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I have a DVM and yes I can use it do you think this psu would work on my K40? Amazon.com

I have a C3d controller

This looks like a setup for a Moshi board controlled laser. Can you please give us a picture of the controller board and that will let us know more about what the rest of the system is about.

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this is the board that came with the machine

C3d, good choice.
Yes that supply should work.
Do you also have a separate 24v supply?

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Yes, for the c3d I do! Great I will place the order today

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