How to repair or replace this micro switch please?

Thread Starter

georgioh

Joined Jun 24, 2020
19
Hi,

I've got a device which monitors the sleep. It's a very tiny one. Unfortunately I broke the microswitch that allows to start it.
I'm a noob in electronics. I think it's not a common on/off switch, here is what it's doing :
- long press : switch on the device
- long press : switch off the device
- short press : toggle between different modes on the LCD screen

Here is the device (approx 3cm x 1cm)
1.jpg

Zooming on the broken switch :

2.jpg

The switch was something like this one (around 2mm):
3.jpg

Currently to start the device I use the tip of a screwdriver to make the contact between the 2 metallic parts (green arrow).
I know I won't be able to replace the switch by a new one because it's too tiny and I don't have any microscope to see what I'm doing (I just have a big soldering iron) so I'd like to find a solution to be able to replace it by another system, even if it's ugly. Like for exemple putting one bigger switch next to the battery... Is it possible?
If you have any idea please share I really like this device and would like to save it from trash.
Thank you very much !
 

Externet

Joined Nov 29, 2005
1,519
It looks like a momentary switch. Abundantly available in most defunct or derelict cellular telephones nearby spider webs waiting to be salvaged. The skills to remove/replace must be there for the task.
 

Thread Starter

georgioh

Joined Jun 24, 2020
19
It looks like a momentary switch. Abundantly available in most defunct or derelict cellular telephones nearby spider webs waiting to be salvaged. The skills to remove/replace must be there for the task.
Yep but I don't have those skills that's why I'd like to do something to replace the "functions" not the switch. Maybe deporting this switch and solder a bigger one to the battery, would it work?
 

Externet

Joined Nov 29, 2005
1,519
Nope. Switching the battery will not restore the (momentary contact) functions. You need the skills, and the proper soldering iron, perhaps from someone else. Hard to find a kid with good eyes and dexterity that knows soldering these days... they are all playing nintendos. :(
 

MrSoftware

Joined Oct 29, 2013
1,824
That would be easy for someone with experience to swap. If you have an electronics repair shop near by see if they'll fix it for you. If you want to be a step ahead, see if you can find the part on digikey or mouser and order a few. I'm not sure where you're located, but someone here might be willing to do it for you as well. Worst case if you want to tackle it yourself, get a larger push button (momentary) and just solder some wires between the existing button and your new button. You'll need to figure out which pads or pins on the button to connect though, the picture isn't clear enough to say for sure which you need to solder to. But be aware that this isn't likely to last long, loose doo-dads hanging on by wires typically break off at some point. .
 

Thread Starter

georgioh

Joined Jun 24, 2020
19
Nope. Switching the battery will not restore the (momentary contact) functions. You need the skills, and the proper soldering iron, perhaps from someone else. Hard to find a kid with good eyes and dexterity that knows soldering these days... they are all playing nintendos. :(

ahhh damn You make my hopes go away...:(

I was thinking about putting a little point of tin on the metallic parts so the contact could be permanent, and then use another switch next to the battery to get back all functions...
That sucks
 

Thread Starter

georgioh

Joined Jun 24, 2020
19
That would be easy for someone with experience to swap. If you have an electronics repair shop near by see if they'll fix it for you. If you want to be a step ahead, see if you can find the part on digikey or mouser and order a few. I'm not sure where you're located, but someone here might be willing to do it for you as well. Worst case if you want to tackle it yourself, get a larger push button (momentary) and just solder some wires to each sides of the existing button. But be aware that this isn't likely to last long, loose doo-dads hanging on by wires typically break off at some point. .
aaah my hopes are coming back thanks :)

When you say "just solder some wires to each sides of the existing button", I don't know if it will work because one time I inadvertly touched one of this side with the screwdriver and the battery started to smoke.

I found the same switches online but the problem is soldering it. And electronic shops in my country will do it for the price of the device... I'd prefer a DIY solution if any...
 

MrSoftware

Joined Oct 29, 2013
1,824
I edited my comments in regards to where to solder the wires. You just need to figure out which pins on the button are connected when the button is pushed, and those are the pins you will solder to for your new button. Look at the face of the button. There are two separate pieces of metal, most likely pushing the button would just connect those pieces of metal. Use your ohm meter to figure out which pins on the button are connected to each of those two pieces of metal, and those are the pins you would solder your new button to. Remove the battery if possible before you start poking around, one slip with the probe or soldering iron could potentially zap something leaving you with a much bigger issue.
 

Thread Starter

georgioh

Joined Jun 24, 2020
19
I edited my comments in regards to where to solder the wires. You just need to figure out which pins on the button are connected when the button is pushed, and those are the pins you will solder to for your new button. Look at the face of the button. There are two separate pieces of metal, most likely pushing the button would just connect those pieces of metal. Use your ohm meter to figure out which pins on the button are connected to each of those two pieces of metal, and those are the pins you would solder your new button to. Remove the battery if possible before you start poking around, one slip with the probe or soldering iron could potentially zap something leaving you with a much bigger issue.
Thanks for your help MrSoftware !
This stuff is so tiny I don't even know where to put the ohm meter
Sorry for the blurry pic I had to zoom a lot with my phone to take the pic

 

Externet

Joined Nov 29, 2005
1,519
Last edited:

Thread Starter

georgioh

Joined Jun 24, 2020
19

You are right it's only the plastic part that is missing (the black one).
Honestly I'm so noob all the switches look the same for me :)

Maybe I can solder wires here to make the contact when I want to ?
 

Externet

Joined Nov 29, 2005
1,519
The marked red is frame support, does not look like an electrical connection. If you are unskilled do not guess poking here and there; much less with the battery still connected.
Electronics works with densely packed smoke inside integrated circuits. If you cause the smoke to escape, it will not work any more.
 

Thread Starter

georgioh

Joined Jun 24, 2020
19
The marked red is frame support, does not look like an electrical connection. If you are unskilled do not guess poking here and there; much less with the battery still connected.
Electronics works with densely packed smoke inside integrated circuits. If you cause the smoke to escape, it will not work any more.

Yes it's a wise advice.
I don't want to do something wrong, that's why I'm seeking for advice from those like you who know their stuff :)

Maybe joining the 2 green marks then? well first, before soldering anything, I could measure with the multimeter but I don't know what to measure exactly.
 

Thread Starter

georgioh

Joined Jun 24, 2020
19
Ideally it would be great to put wires here, but it's impossible to solder something here, not enough place, the tin will recover everything...
 

Externet

Joined Nov 29, 2005
1,519
Abstain from guessing. Look for skilled help. Spend some time looking for the proper part. This is not life support equipment that needs to work now by rigging a mikymouse fix that will last a couple of button pushes and die again or damage traces on the board.
 

Thread Starter

georgioh

Joined Jun 24, 2020
19
I don't have any skilled help around me unfortunately. If I find where to solder wires and deport the contact somewhere else it will be a long lasting fix, because when I'll put back the device's case everything will be protected.
It's a device that monitors oxygen in blood during the sleep, and vibrate when it's too low (meaning the sleeper is in apnea, a dangerous state) that's why I'd like to repair it. It's not expensive enough to justify bringing it to a repair shop.
 
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