Omega Cal. 1441 Replacement

Hi. I have an Omega Constellation circa 1987 with a Cal. 1441 movement. The watch does not run after a battery replacement and I'm assuming its an electronics issue since it worked fine before it ran out of battery and sat for a couple of years. I'm relatively handy working on mechanical movements and have replaced a few Japanese quartz movements, Seiko, Citizen, etc., but no experience in repairing quartz movements. A replacement 1441 or the equivalent ETA 255.561 seems impossible to find but according to my research the Cal. 1438/1538 or ETA 255.461/462 are direct physical substitues. Please correct me if I'm mistaken. I can get a new ETA 255.461/462 but the specs indicate 23.3 mm outside diameter and the Cal. 1441 measures 23.9mm. There's a spacer ring that fits around the movement when it is installed in the case and I'm wondering if I need a larger ring or I'm misinterpreting the dimensions. Any help is appreciated. Thank you all.

First the diameter is not the only possible problem.
So which issues your preBond movement have?
Pictures are welcome 😉

I recently had a 1441 repaired after it had stopped working - my local watchmaker was able to do it - a lot of the parts for these 1441 movements seem to still be available...I even saw a place selling the eta 255.561 circuit boards online a short while ago - $70 I think, I'm guessing it would work with the 1441? Perhaps your best option would be to seek out a local watchmaker and see if it could be repaired? Good luck with it all anyhow!

I suggest a repair also it would be a real pity to to get rid of that high-end quartz movement.
As you may know it`s one of the "holy three" twin quartz movements but beside the ones from Citizen and Seiko that from Omega is the best maintainable.

Thank you all. My preference is obviously to have it repaired and keep the watch as original as possible just because I've owned it from new. I did see the replacement circuit mentioned above and may ultimately order it but I would still like to know if the 255.461/462 is a direct (physical) replacement for 1441. All online references show the same exact dimensions, e.g., 23.3mm diameter, 2.45mm height, etc., for both 255.561 and 255.461/462 which makes me very curious as why I measure 23.9mm. Thanks again.

That can maybe or maybe not but it`s not thermocompensated and so I tend to think parts are not easy interchangeable additionally think of the fact that the 255.461/462 production start was `roundabout 2007.
Here are the tech sheets:
https://www.watchuseek.com/attachments/eta-255-461-pdf.15603823/
https://www.watchuseek.com/attachments/eta-255-511-255-561-pdf.15603822/

Best thing is that you start to describe whats wrong with your movement.

Thanks for the reference documents. They also confirm that the two movements have identical dimensions. As for "parts" interchangeability, I'm not as concerned since I'd be swapping the entire movement. Well, as for what's wrong with the movement, all I can say is it has stopped running. I wish I could be more specific but unfortunately I neither have the test equipment nor the experience to isolate the root cause any further. All I can do is to isolate between mechanical and electronic and that is my focus right now. More specifically, there's a "lever" underneath the electronic module that touches a certain spot on the board and stops the watch when the crown is pulled to the time setting position and is then moved out when th crown is pushed in. I'm looking into the lever/keyless works mechanism to make sure that's not the issue. Maybe going down a rabbit hole...

Maybe we should start with the electronic basics I could guide you through if you want to?

So you said that you stored the watch and the battery was runnin`empty - did the old battery going leak? Was there acid onto the movement?
Which battery did you chose as new?
Are you sure that the new battery is fully loaded? Have you the possibility to measure the voltage of the new battery (should be 1.55V)?

No leaks, exact brand new Renata replacemet battery fully charged. I have also tested all the traces on the electrnic module circuit for continuity and all checked out. If anyone has information on more detailed measurements, e.g., resistance across the coil, oscillators, etc., that would help me in isolating/confirming the fault in the electronic module in which case I can confidently order a replacement.

OK you never mentioned that you are no beginner.
BUT did you measured the battery?

Next step would be locating the failure into the mechanic or the module.
If you like I dont have access to a some kind of professional movement tester I use this smart device:


So you can have evidence it`s ever mechanic or electronic fault.
Sometimes Watchmaker or Jeweller shops who change watch battery have such a device.

If all hands are moving when you press the button then the failure lie within the electronic in that case it would be nice if you have an old compass ( no not an app on your cellphone 😉).
The hand of an compass is sensitiv enough to shake if the impuls from the quartz goes to the module.
If not I would disassemble the coil and measure it for it`s resistance.
Very often the one who have changed the battery have damaged the coil 😉.

Report here how is it going.

Thanks again for the input, appreciate it. The quartz movements are generally inexpensive and do not warrant spending a great deal of time trying to troubleshoot the issues and replace parts, etc. I have done that several times in the past with great success. I consider myself a beginner watch hobbyist/collector but have gathered enough tools to service/restore mechanical watches. Most recently I restored my dad's 1956 Omega Seamaster - Cal. 471, and a 1972 Seiko Chronogragh (Cal. 6139B) I have owned since highschool as well as a couple of pocket watches. I purchased the Constellation back in 1987 and wore it off and on and it basically sat on the sidelines. Anyway, at this point I think I have ruled out all the obvious causes and need to decide which direction to go. The last troubleshooting step I can take is take some voltage measurements across different points on the module but that's a bit challenging since the majority of the measurement points are underneath the board so I need to somehow power up the module off the main plate. The replacement electronic module is readily available from a couple of sources for around $60. I can also get a new replacement ETA 255.461/462 for about $110, assuming its a direct replacement, albeit with a lesser technology when compared with 1441/255.561. I still wonder why Omega used this movement for such a short period making it almost a unicorn.

Here you go…
https://www.watchmaterial.com/eta-255-472-255-511-255-561/

Thanks, that's great, hopefully it will work for you. It's too bad it's not a direct fit for the Omega 1438/1538 because it could be used to upgrade these watches. A while back I bought a TC Longines to do that with the 1538 in my SM300.

AFAIK Omega build in twin quartz movements 1988/89 only in that time it was some kind of old technology compared that Seiko have done that rondabout then years earlier. Even the cheapest quartz movement produced automaticaly nowadays flying in million pieces out of automatic production is more or even average accurate then the twin quartz movement.
So all in all it was just a matter of cost reduction.

But for the collector view you have a complete original prebond so it is worth any afford to hold on it like this.
Obvious its your choice indeed but I wont help destroying it.

There have been very few thermocompensated quartz movements over the years, the only way to achieve +/- 10 spy accuracy. The 1441 is one of them, but yes the way it does it was improved on around the time of its release with the use of only one thermistor instead of two.

Thank you guys. I did some additional testing last night and using an analog voltmeter I could detect the pulses; the needle pulsing so slightly but consistently, on the leads going to the coil. So at this time a faulty/damaged coil is the primary suspect. I'll look more closely at the coil under a microscope to confirm. I'll post a picture of the watches I recently restored as soon as I figure out how to do it. Looks like I can' just drag/drop from my pictures folder.

It would be great if you could repair it - the 1441 was really a chronometer grade movement, but I suspect it didn't get certified because of the marine chronometer - which used a non-tc quartz - the accuracy of both movements was apparantly pretty similar...