Still Not Working After New Battery...

[eezy]

To reiterate about checking batteries - I put a new Renata in Mrs eezy's Mirvaine diver watch when it wasn't working. It still didn't work even though the battery lit up my tester and went in the drawer. 

I just fetched it out to investigate, checked the ''new'' battery I previously fitted and it is reading 0.751v. Fitted a battery from a different batch after checking voltage at 1.59  and it's working fine.

Lesson learned - in future I'll get my batteries from Cousins or HS Walsh and check voltage before I fit them.

[watchweasol]

Hi   As a matter of course when changing batteries I always check the movement works, and the old battery is u/s, having verified that it works check the new battery 1.55v and fit it. Simple checks as there are batteries out there that are not what they seem, in some cases not the genuine thing.

[rodabod]

Loads of fake batteries about these days. My mother got scammed buying “Duracell” on Amazon even. I get mine from Cousins. 

[JohnR725]

Here's an interesting machine priced at £370.00. It appears to do just about everything you want for quartz watch testing.

 

https://www.cousinsuk.com/product/horotec-flashtest

[boyandhisdogs]

Yesterday I took off the uppermost cover (from the back) and the circuit board. This was just enough that I could see the wheels and keep the non-metals away from the lighter fluid. I put what was probably too much lighter fluid on the wheels and surrounding area, let it sit for about 10 minutes then lightly blew it dry with computer duster. 

And... nothing changed. The watch is still showing a tiny pulse across the coil on my multimeter, the battery still reads 1.59v, and the watch still does not turn. 

 

I ordered a replacement movement for a whopping $15 just so I can get the watch back together and start wearing it, but I want to keep tinkering with the old movement until I fix it... or break it... I'll either fix it and put it in something else or take it apart and put it back together just for the experience. 

[HectorLooi]

This might sound like a weird suggestion. But if you watch some of Le Arsi's videos on YouTube, he reverses the polarity of his tester for a moment, i.e. connects +ve to -ve and vice versa. I tried it a couple of times on "dead" movements and they came back to life. It doesn't work all the time. But what is there to lose on a "dead" movement anyway?

[JohnR725]

5 hours ago, boyandhisdogs said:

The watch is still showing a tiny pulse across the coil on my multimeter, the battery still reads 1.59v, and the watch still does not turn. 

There seems to be something missing from this discussion? The batteries fine that's the correct voltage for a silver cell looks barely been used. The impulses are wonderful but did you check the coil resistance yet? It's extremely easy when changing a battery to bump into the coil and coils are very very sensitive to things touching them that wire is very very fine. So a lot of times the damage is not obvious you have to look really really carefully but managing to resistance would be good.

[HectorLooi]

If the coil is open, you will still get a reading on a multimeter. The simplest way to test whether there is a pulse to the stepper motor is to use a quartz watch pulse tester. This same tester has a "line release" function which can test whether the mechanical parts of the watch are working properly. 

[jdm]

7 minutes ago, HectorLooi said:

If the coil is open, you will still get a reading on a multimeter.

I don't think so, the reading will be OL (Open Loop). Otherwise something between 1 and 2 KΩ.

Edited August 23, 2020 by jdm

[watchweasol]

There is the possibility when testing in situ to get feedback through the circuit, to get a true reading remove the coil from the watch and test on its own a reading of 1 or two ohms coin good  no reading open circuit wire, it you can see the break (look for a bright scuff mark) it is possible to repair with conductive paint

[JohnR725]

1 hour ago, watchweasol said:

There is the possibility when testing in situ to get feedback through the circuit, to get a true reading remove the coil from the watch and test on its own a reading of 1 or two ohms coin good  no reading open circuit wire, it you can see the break (look for a bright scuff mark) it is possible to repair with conductive paint

I seem to be a little confused here today?

If the meter is set to voltage or in the case of an analog meter you can also do with the microamp scale and you place it on the coil leads you will bill the see that the circuit is producing a pulse out. But that does not tell you if the coil is good. You need to have the battery out the volt ohm meter you measure the resistance is usually somewhere in the around 2000 home range.

The other way is to make relatively inexpensive devices to pick up the magnetic impulse but that isn't always reliable. We had that at work the other day it showed up on the witschi as producing pulses the little LED lit up but the coil was still scratched in the watch still didn't run.

That ideally the best way to do coil resistance is to take the circuit off even though you can do it with a lower voltage taking the circuit off is always nice if you can otherwise you just make sure the meter isn't producing too much voltage otherwise the circuit can turn on or conduct and you go get false readings.

 

[watchweasol]

The circuit block will produce pulses if in good condition,  Whether the coil is attached or not, as proven by the  witschi  the pulses induce the current  in the coil and move the stepper motor  As you noted with the meter set to micro amps scale and attached to the coil contacts the needle will pulse in tune to the circuit block output as long as the power is applied to the circuit. An open circuit coil will not react to these pulses and the stepper motor fails to turn. The best way to avoid false readings is indeed to either remove the circuit block and test the coil or remove the coil and test on its own

[jdm]

22 hours ago, watchweasol said:

As you noted with the meter set to micro amps scale and attached to the coil contacts the needle will pulse in tune to the circuit block output as long as the power is applied to the circuit.

Going by the book the meter has to be set to Volts when checking for pulses. As noted above it will also show pulses if set to current, but will indicate the current that traverses the instrument, and that is not a value useful for diagnostic, while voltage might be. Refer to page 9 of the attached document. One needs an analog multimeter with null current setting for this test, fortunately these are quite cheap nowadays.

 

955114.pdf