Seiko 4633 step rotor:(

[jojo]

Hey guys I'm new to fixing watches. I need some help or advice with fixing my Seiko 4633. I believe the issue lies with the step rotor here's the piece I'm referring to (https://www.ebay.com/itm/162543866751). Whenever I put the battery in, the second hand just barely goes back and forth and I think the root cause is the step rotor "jumping" out of its seat. Taking it apart and putting the battery in I saw that it jumps out about halfway and then barely rotates back and forth. Any advice?

[watchweasol]

Hi welcome to the forum,   It might just be a piece of dirt in the train or even gummed up oil in either case requires servicing, but before we run that road a few checks.  Put a little drop and I mean a little on the bearings for the train, if it’s sticky oil this will thin it temporarily, if it# dirt put it on a line release tool ( plenty on eBay) and spin the train and hands round. If that’s successful put on a battery and test. If that fails may be the coil or circuit board faulty.  Depending on the watch might be cheaper replacing the movement but that requires some tools and a modicum of skill.

post picture# of the watch movement front and back for further help.

[RichardHarris123]

Hello and welcome.  We usually introduce ourselves on here.  I don't work on quartz watches but someone on here will help you. 

[Nucejoe]

 If not a weak battery, turn any gear of the train you have access to, encouraging  the train might free it.

 

 

[watchweasol]

Hi joes advice is good but be very careful with the probe you can damage teeth if you are rough?

[Neverenoughwatches]

1 hour ago, jojo said:

Hey guys I'm new to fixing watches. I need some help or advice with fixing my Seiko 4633. I believe the issue lies with the step rotor here's the piece I'm referring to (https://www.ebay.com/itm/162543866751). Whenever I put the battery in, the second hand just barely goes back and forth and I think the root cause is the step rotor "jumping" out of its seat. Taking it apart and putting the battery in I saw that it jumps out about halfway and then barely rotates back and forth. Any advice?

Pretty sure the step rotor does not go back and forth, it should revolve around continuously in its bearing, turning at every magnetic activation of the stator. The rotor is the basically the driveshaft of the train, the equivalent of the barrel in a mechanical watch. If you are correct and it is jumping out of it seating then its pivot is either broken or the pivot bearing is damaged, the bridge is loose or the rotor has started to disintegrate. 

2 minutes ago, Neverenoughwatches said:

Pretty sure the step rotor does not go back and forth, it should revolve around continuously in its bearing, turning at every magnetic activation of the stator. The rotor is the basically the driveshaft of the train, the equivalent of the barrel in a mechanical watch. If you are correct and it is jumping out of it seating then its pivot is either broken or the pivot bearing is damaged, the bridge is loose or the rotor has started to disintegrate. 

A picture of the rotor and its adjacent parts would be in order really.

[jojo]

2 hours ago, jojo said:

Hey guys I'm new to fixing watches. I need some help or advice with fixing my Seiko 4633. I believe the issue lies with the step rotor here's the piece I'm referring to (https://www.ebay.com/itm/162543866751). Whenever I put the battery in, the second hand just barely goes back and forth and I think the root cause is the step rotor "jumping" out of its seat. Taking it apart and putting the battery in I saw that it jumps out about halfway and then barely rotates back and forth. Any advice?

So here the pin and the watch open, maybe I'm making a newbie mistake but the gif explains the second-hand movement when I put the cover back on, the only other issue I can think of is that I don't have the plus terminal B of battery connection, I only have plus terminal A. 

 

 

Edited January 4 by jojo
more context

[watchweasol]

Hi. The rotor or step motor receives pulses from the bloc as a square wave form , posative and negative. This causes the rotor to turn for each pulse received at one per second intervals. So as the rotor part steps would lead me to think there is a blockage within the train,  so clean/ service the movement lubricate and re try. Unless you have or have access to a scope or a meter to be able to monitor the pulses  it will be dificult to diagnose other than changing parts. Ie. Coil and bloc.  With a meter  on the coil contacts . Be careful of the thin wires.  You should see the meter needle deflect for each pulse.  There are cheap devices# on eBay that will do this as well as a few other things. But first service the watch to eliminate dirt and oil problems then there will be a need to dig deeper.

[Neverenoughwatches]

24 minutes ago, watchweasol said:

Hi. The rotor or step motor receives pulses from the bloc as a square wave form , posative and negative. This causes the rotor to turn for each pulse received at one per second intervals. So as the rotor part steps would lead me to think there is a blockage within the train,  so clean/ service the movement lubricate and re try. Unless you have or have access to a scope or a meter to be able to monitor the pulses  it will be dificult to diagnose other than changing parts. Ie. Coil and bloc.  With a meter  on the coil contacts . Be careful of the thin wires.  You should see the meter needle deflect for each pulse.  There are cheap devices# on eBay that will do this as well as a few other things. But first service the watch to eliminate dirt and oil problems then there will be a need to dig deeper.

I would say the cleaning and lubrication has more effect here in a quartz watch than in a mechanical watch. The train is much smaller, the torque must be less. An amount of dirt and debris will stop a quartz train sooner than a mechanical train although the hairspring of mechanical is more susceptible .

17 hours ago, jojo said:

So here the pin and the watch open, maybe I'm making a newbie mistake but the gif explains the second-hand movement when I put the cover back on, the only other issue I can think of is that I don't have the plus terminal B of battery connection, I only have plus terminal A. 

 

 

What was the jumping out of it's seat rotor problem ?  Did it just look that way ?

[watchweasol]

Both pivots on the rotor . Pics supplied.  Look good. Might be a worn bearing / jewel. .?

[HectorLooi]

Twitching of the rotor could be due to mechanical or electrical problems 

Do a complete disassembly clean the pivots and peg the jewel holes. Check that the coil resistance is correct. Check pcb for oxidation and corrosion.

Fit only the rotor and check that it is able to rotate 360°.

If it is ok, then do a complete assembly and oil. I use Moebius 9000 for the gear train.

Edited January 5 by HectorLooi
Typo

[Nucejoe]

On 1/4/2024 at 9:45 PM, jojo said:

 Whenever I put the battery in, the second hand just barely goes back and forth 

This indicates good electric circuit in the coil.

Now that its partially disassembled you might as well fully disassemble/ clean/ check all holes/ pivots/ gears.... 

If you don't have moebius 9000 , any light watch oil will do.

When the rotor is loose on bench like you show in picture , it will attract bits of metal.

Rgds

[Jon]

I've got a Heuer 1000 with an ESA 563.121 movement that is doing the same. I've just got it on the bench tomorrow so haven't worked on it yet, but after I've electrically tested it I'm going to strip it and find the problem. The very fact that the second hand is jumping back and forth by a quarter of a second indicates power is getting through the coil and PCB. I'm guessing it is a problem with the rotor, as the gear train feels pretty free to me and turns easily. I use Moebius 9030 to oil quartz movements, but anything with a low viscosity will work. if you only have 9010 that'll work, but 'ghost oil' the train. So, this is barely oiling the gear train jewel with the littlest amount of oil possible. Cartier doesn't even oil the train at all, as there is so little torque they feel it is needed, which in some respects is true.