# Esa 9158 Dynotron



## Bob66 (Jan 10, 2011)

Hi.

Amongst the job lots of watches i've bought on Ebay recently was a gold plated Havers with a ESA 9158 Dynotron with day and date movement.

It was a suprise as it's the first i've seen.

Someones already had a bash at it as some parts are loose inside but it seems complete.

I tried a battery in it and the balance runs when it wants to but when it stops i can see the balance creeping or trying to move.

I've tried searching for parts lists and repair instructions but have only found lots of pics.

I would like a pic of the area under the brass plate by the crown as that's where the loose bits go including a

flat(ish) spring.

And any help on testing the eletronic parts would be great.

Hope you can help.


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## Silver Hawk (Dec 2, 2003)

If the balance is oscillating a little, you probably do not need to test the electronics.

But these movements do need to be scrupulously clean if they are to run smoothly. If there is any friction / resistance in the gear train due to dirt etc, you will often see the balance running smoothly and impulsing the index wheel with each swing, but the index wheel then falls back to the same position due to resistance in the rest of the train.


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## Bob66 (Jan 10, 2011)

Hi.Thanks for replying.

The balance runs strongly for a while then stops but it's only driving the index wheel at the moment because i removed the next 2 gears as they were loosely fitted along with some other bits so i think i removed the chance of friction further along.

I don't know the name of all parts as i'm a bit new to all this.


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## Silver Hawk (Dec 2, 2003)

Bob66 said:


> The balance runs strongly for a *while* then stops but it's only driving the index wheel at the moment


How long is a "while"? :huh: seconds? minutes?

If it runs and you've only assembled the balance and index wheel and you're sure you have good, oil-free connections from battery to circuit board, then it probably is a problem with the circuit board....but I have never experienced this...it usually *is* something else.

If it doesn't run at all, then yes, circuit board / coil.


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## Bob66 (Jan 10, 2011)

The longest it has ran is about minute.

At the moment it's not running


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