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ETA 955 Service Walkthrough "The Workhorse of Highend Quartz" The ETA 955 and 956 Quartz Movements are the most commonly found movement in high-end quartz watches with three hands and a date feature. You will find them in Omega, Tag, and many other brands on the market. For this walkthrough I will be using an 955.412 Movement as my example; but the 956 is so similar to the 955, that this walkthrough will suffice for both. Please note that the numbers after the decimal place only relates to the factory in which the movement was made, so yours could read 955.112, or another factory number ... regardless, the parts are identical and interchangeable. As with all movements, quartz or mechanical, they have a service interval that should be adhered to for longevity of the movement. With quartz movements when the lubrication becomes dried out, or the movement becomes dirty, they will draw more and more current from the battery in order to maintain accurate time keeping. The ETA 955/6, when in optimum condition should draw around 800nA ~ 1.5uA, if the movement is drawing more power than this, a service is required. If a service is not performed, the battery life with decrease markedly, and can go as far as drawing more power from the battery than it was designed for, and damage the battery and cause it to leak and corrode your valuable time piece. Service Manual for the 955/6 Movement CT_956412_FDE_493024_06.pdf.PDF Disassembly Remove the two Date Wheel Keepers. I always start with the one holding the Date Jumper Spring in place. Sometimes the Date Jumper Spring can ping out of place, so be careful when removing the keeper plate above it. Here is a reference photo in case it moves before you see how it's properly seated. Next remove the Keepers and Date Wheel. Then remove the Date Jumper Spring, Motion and Calendar Work. This will leave only the Keyless Work; remove the Yoke and the Sliding Pinion only. We need to flip the movement over, and disassemble the IC Board before we can remove the rest of the Keyless Work. With the movement flipped over, remove the 3 screws holding the Coil Protector. Note for re-assembly the Gold Screw in the centre. Now that the Coil Protector is removed, GREAT care must be taken not to damage the exposed fine windings of the Coil. Then to remove the IC Board, simply remove the 2 remaining screws that hold it. Do this slowly and carefully, as you do not want to slip off the screw and damage this delicate circuit. The same level of care needs to be taken when removing the IC Board from the Main Plate. Take your time and carefully lift it off and store it immediately out of harms way. Next remove the black Insulator Block, and Battery Insulator. This will expose the Setting Lever Spring Clip, which will enable you to remove the rest of the Keyless Work. To remove the Setting Lever Spring Clip, place both points of your tweezers on the locations where I've placed the stars and gently push down on the spring. Then with a piece of Pegwood, push the spring in the direction of the arrow until it moves to the larger opening slot. This will now allow the Setting Lever to be removed, along with the rest of the Keyless Work. Next remove the Stop Lever and Switch, and remove the one screw holding the Train Bridge in place. Then carefully remove the Gear Train and the Rotor. The movement is now completely stripped and ready for inspection and cleaning. There are some parts that you do not place in the parts cleaner, they are as follows: Date Ring Rotor IC Board The rest should be demagnetized prior to cleaning to avoid any metal particles in your cleaning solution from sticking to your parts. When cleaning I also including the Insulator Block, and Battery Insulator in the basket, normal watch cleaning solutions do not harm these items and it is essential they are completely clean to provide the best insulation possible. The Rotor should be cleaned by use of Rodico. As you can see from the picture below, it's surprising the dirt and old oil this will remove ... and it is sufficient cleaning for the Rotor. I hope this has been a help to you, and I will post the assembly procedure later today, if time permits.