Reassemble 4 button piano switch

Thread Starter

Robert Micallef

Joined Sep 4, 2019
5
I bought this switch to replace a broken one on a fan. The broken switch had the electric contacts protruding outside of the switch on which one can solder the electric cables but this one didn't. So I took apart this switch as I wasn't sure how to connect / solder the electric cables (I still am not sure) and it fell apart and I cannot figure out how it should be assembled again. Does anyone know please?

 

RPLaJeunesse

Joined Jul 29, 2018
83
Take more pictures, much closer up, front & back of all pieces! Where did the switch come from? Part number? Fan make & model? Fan front picture, showing switch pushbutton labels? How is the fan wired presently? Right now I can only guess the switch back has "poke home" wire connections that work with wires that are simply stripped, no connectors required. In your picture the long metal piece is the latch bar, it probably goes toward the right side of the (as shown) switch body. The spring goes on the top bump of the latch bar and sits at "OFF" button end of the switch body. No idea where the smaller metal parts fit.
 

Thread Starter

Robert Micallef

Joined Sep 4, 2019
5
Thanks for the replies. I am not hopeful to get this back together if I'm being honest but I thought I'd try.

@MaxHeadRoom I took it apart because the holes where the cables should go have the contacts retracted quite a bit. I am not sure how one can safely attach these cables as there doesn't appear a way to screw them to hold them in place and the contacts are too retracted with the hole too small to solder. So I opened it to see if there is something I'm missing. Something I now regret. The old (broken) switch had metal brackets protruding from inside which one can easily solder the cables to.

@RPLaJeunes I know where the white vs gray buttons go. The fan make is Edimax. I don't know the model. Currently the fan has the ground soldered to where the white button would be and three different live cables soldered where each of the gray buttons go.

Here are more pictures:

RobertM_switch.png

Moderators note : reduced size of pictures with the essential parts.
 
Last edited by a moderator:

Thread Starter

Robert Micallef

Joined Sep 4, 2019
5
It is possible the live is soldered to the white button not ground. It is black in colour so I think it is the ground but the switch has L on it. It doesn't really matter though since I would put the cables on the switch in the same order they currently are.
 

RPLaJeunesse

Joined Jul 29, 2018
83
Definitely "no soldering required" connections. Stripped wires are just pushed into the holes, where the springy contact metal grabs into it. The assembly is obvious to me except for the two smaller metal pieces. Spring goes on latch bar at the white button end, the end with a ramp but no hook. What you call ground is the switch common, that connects to the "hot" (more correctly "line") wire. The white button goes at the switch common end. The smaller metal pieces are probably interlocks to prevent pressing 2 adjacent buttons down at once, but it's not obvious to me how they do that job.
 

Thread Starter

Robert Micallef

Joined Sep 4, 2019
5
Thanks for the replies. I have figured out a bit how it works and how the long metal thing should be placed so the buttons click into place and get released using the white button. I have also managed to close it and get it somewhat working.

The problem is it only works if upside down otherwise the gray buttons won't stick down. So it is only working thanks to gravity which I'll be the first to admit that this is not ideal. And if I rotate the switch I can hear the metal bits moving. So I think the smaller metal bits maybe somehow hold the longer one from moving or I am missing something.

I won't be home for a few days so I cannot try again until next week. I'll update the thread if I figure it out.
 

ci139

Joined Jul 11, 2016
1,088
it's obvious (at least should) from the exploded view that each button dis-engages whatever there was active and locks conducting while the white one releases all contacts ...

it shouldn't be orientation dependent = don't force it to case before you are sure it is re-assembled right
(while ago it took me several hours to figure out how to ... in which order to reassemble a door lock -- it was tricky but eventually not impossible)

... there likely is possible to lock down all combinations of singles to a triplet of the buttons -- likely -- should not be tested under live circuit !!!
 

Thread Starter

Robert Micallef

Joined Sep 4, 2019
5
So I figured it out (mostly). I re-assembled the switch and it is working well. The grey buttons stay in place and get disengaged by the white or another grey button. I tried what you told me and just pushed a stripped wire in those holes and yep it just stays there. I replaced the switch for the fan and it is working well. The only unknown are those two small metal bits. But hey it works.Thanks everyone for your help.

In case someone else has this problem:

The spring goes at the end of the metal bit (let's call it zigzag bit) as shown in #1. The zigzag bit is then placed with the spring against the housing as shown in #4. The way it works when you push one of the grey buttons the metal bit marked with the yellow asterisk in #2 pushes the zigzag bit backwards and the spring then pushes the zigzag bit forwards to hold the grey button down in the bit marked with a yellow asterisk in #1. The way it works if you press another grey button it will first push the zigzag bit backwards releasing any other grey button, and then it is held in place where the yellow asterisk is. If you push the white button all it does is push the zigzag bit backwards where the pink asterisk is which releases all the buttons. There are holes in the housing where the metal bits of the buttons go into marked with a green asterisk in #4.

I wasn't sure where the two small bits go so I just put them between the zigzag bit and the plastic housing where the blue asterisk is in #1.




 
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