Benrus

[Jeff117]

I have gotten bit by the collecting of watches bug. I am fascinated by all the watch repair videos and find most to be very relaxing. As my collecting proceeds I was passed down a watch from my late father. Nearest I can tell its a cheaper model Benrus quartz watch. There are no identifying marks on the back and apparently it opens from the crystal side of the case. Can anyone offer any information. I'd like to know the model or time of manufacture. I'm probably not going to get it working. This is for sentimental purposes. Thank you.

[jdm]

Just try a fresh battery, chances are that it will work. If it doesn't start try some quick spinning on it axis, and pulling the stem out and in. If no luck I think the back is removable to identify and replace the module. A new strap and it will be a nice watch to wear.

[MrRoundel]

The battery access hatch looks to me to be of the type that was used on electronic watches of the early seventies, perhaps late sixties. If I'm right, and it does say "Electronic" at the bottom of the dial, it probably has a movement in the ESA 9150 line. 9150, 9154, ...They are interesting in that they are battery powered but keep time via a balance wheel rather than a quartz impulse. They are often fixable, but are a bit finicky. And my experience with an ESA 9150 that I actually got running is that it run fast. This MAY be due to the battery it was designed with was in the 1.35V range, which are not longer available. At least I couldn't find one. It may also be due to something being amiss with its hairspring. (?)

Look up "ESA 9150" and/or "ESA 9154", and you'll see what they look like, and perhaps what to expect. Good luck.

 

[Nucejoe]

I put a bit of lighter fluid on each pivot ( jewel), let run for an hour, then apply oil to same pivots. It usually needs a battery to run.

This watch is inexpensive, not cheap.

 

[MrRoundel]

This is a Benrus Electronic that is an  ESA 9154 movement. My feeling is that this is what you'll find when you are able to open it up. There are magnets on the balance that sometimes attract and capture any screw that dares come loose in their vicinity. The one I got running had two screws stuck to the magnets at the balance, IIRC.

 

[Klassiker]

What material is that balance wheel?

[MrRoundel]

37 minutes ago, Klassiker said:

What material is that balance wheel?

I wish I knew. I looked in the ESA 9150 technical manual and didn't see any notation on what the material was. I touched a magnet to it and it was not attracted to it.

[MrRoundel]

Oh, and according to this specialty website, the movements are transistor controlled.

Electronic Watch Site

Better reference

Edited June 26, 2020 by MrRoundel
Add second link.

[HSL]

I think one can take a look at the previous posting of a Benrus like this,
Rogart63 added an link showing the service of this movement...