a DT9205A DMM metal clamps order

Thread Starter

Med Erabti

Joined Jan 11, 2018
3
Hi, I was oiling the power on/off button and while doing that I messed up the metal clamps order on the rotary knob to PCB conductive area as shown:

Anybody has the same DMM?
Thanks in advance!
 

Thread Starter

Med Erabti

Joined Jan 11, 2018
3
It started to stuck after a certain times of pressing it.
I already got a new meter. But I wanted to fix this one instead of collected dust.
The problem is with the order of these little metals. They conduct with the rotary knob on the PCB correspondingly for each DMM mode.
I need someone who has the same model as mine to tell me the specific order of the metals.
Thanks!
 

Lyonspride

Joined Jan 6, 2014
137
That's like a $5 meter, not even worth fixing.

BUT I would say this has been a positive experience, you have learnt something much more valuable than the meter, something that will benefit you greatly in the future (seriously) :)

Always make notes OR mark parts to their locations (colour code any connectors to their connector headers for example) OR take photos of items as you take them apart.

As for what to do with the meter, i'd either throw it away or figure out how to set it as a permanent current meter (surprisingly useful to have).

If your determined then you may be able to identify where they were located using a microscope to look for wear on the plastic wheel, OR you could try every one of the 150 something possible combinations of locations ;)
 
Last edited:

spinnaker

Joined Oct 29, 2009
7,830
It started to stuck after a certain times of pressing it.
I already got a new meter. But I wanted to fix this one instead of collected dust.
The problem is with the order of these little metals. They conduct with the rotary knob on the PCB correspondingly for each DMM mode.
I need someone who has the same model as mine to tell me the specific order of the metals.
Thanks!

Do you mean the missing contacts on the dial??? They are just contacts. Pieces of wire. They are all the same. There is no "order". Just put them back wherever.
 

kubeek

Joined Sep 20, 2005
5,794
I don´t think wherever is correct. The contacts should connect each pair of the pcb pads, so it seems you need 5 contacts on the knob which you have. The only thing you need to find out is on which side they should be (maybe from the pattern on the pcb relative to what functions the meter does where), and I think you could just try it out and see if the meter works properly in all knob positions.
 

MrChips

Joined Oct 2, 2009
30,711
By "metal clamps" you mean the metal switch contacts.

There are ten concentric rings and therefore there are five pairs of contacts which join two adjacent rings when the range switch is rotated.
If you look carefully at how the contacts are secured to the orange plastic, you can see that there is only one way the contacts are secured.

I cannot see from the photos that there is any other way to install the contacts.
What makes you think that they are not in order?

Does the meter not work correctly the way they are installed?
 

Thread Starter

Med Erabti

Joined Jan 11, 2018
3
BUT I would say this has been a positive experience, you have learnt something much more valuable than the meter, something that will benefit you greatly in the future
I assure you I'll put marks next time I disassemble anything ! :)

you can see that there is only one way the contacts are secured.
I cannot see from the photos that there is any other way to install the contacts.
What makes you think that they are not in order?
Does the meter not work correctly the way they are installed?
I just made the continuity works. Other functions don't work.
The order that they're now in is just a guess, which made continuity work.
------------
Thanks guys, I won't give it more tries.
It doesn't deserve the amount of time!
Thanks again.
 

spinnaker

Joined Oct 29, 2009
7,830
I assure you I'll put marks next time I disassemble anything ! :)


I just made the continuity works. Other functions don't work.
The order that they're now in is just a guess, which made continuity work.
------------
Thanks guys, I won't give it more tries.
It doesn't deserve the amount of time!
Thanks again.

Clean with some isopropyl alcohol. Higher concentration the better. There is no "order" to those contacts. They are likely all the same. The only thing that would make them different is their size. And that would be obvious.
 
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