Recalcitrant Watch Back - Any Clues?

[DrRock]

Hi guys :)  A friend has a watch that needs a new battery, and I cannot for the life of me get the back off it.  Any clues or help in removing the back would be much appreciated :)

 

It is a Citizen digital, and on the back, it says:

 

Citizen Watch CO.

 

Water Resist

 

BASE METAL CP.

 

P110-313283 TA

 

3050706

 

GN - 4 - S

 

JAPAN => 6

 

Now from my searching, the P110 suggests it was made in the '70s, and is apparently called the calibre #, but there are no manuals to be found for that.  On the Citizen Web site, it has a long list of calibre numbers, but not that P110 one.

 

The back LOOKS like it should be a screw-off job, with a crab claw or similar.  But that does nothing. The back spins, with some difficulty, and very stiffly.  But it doesn't seem to unscrew.  And the recesses where it looks like the tool should go are actually openings into what looks like a separate layer of the back, which makes me wonder if it in fact needs some sort of special tool to pull the back off?  There is no "lip" to suggest that it's a slip-off back.

 

I'll try to attach three photos - one showing the face, one showing the back (you can see 4 recesses that don't look like typical screw-back notches), and one close-up showing the unusual appearance of one of those recesses - it looks like it leads into a separate layer of the back:

 

 

 

 

—
Pete
====
 

Edited December 27, 2015 by DrRock

[steven]

Hi Pete, it should be a snap back. From your third pic, it looks like the lip is at the "Japan" position.

Sent from my iPad using Tapatalk

[DrRock]

Steve - you're a genius.  I don't know how I missed that.  That was it - I just changed the battery and all works. :)

 

Was a **BLEEP** to get off though - I think it was corroded on.  So when brains don't work, try brute force - that worked!

 

Thanks  - can always rely on WRT for help..!

 

—
Pete
====
 

[Geo]

Hi Pete, the cut outs are to help let the sound of the alarm out, and have nothing to do with opening the back.

It's been a while since we've heard from you, I hope all's well?

[DrRock]

Hi Geo - and a Happy Christmas to all WRT-ers, as well as best wishes for a ripper of a New Year :)

 

All is well - just been very busy at work. Thanks for asking :)  I haven't had the time I'd like to spend stripping down and rebuilding some of those movements I got cheaply from eBay, although I have managed to do a couple.  But the rest will have to wait until things quieten down somewhat.

 

I will check in from time to time (no pun intended), and post when I have something worth contributing, or a question I can't solve, like the one on this thread. :)

 

—
Pete
====
 

[Geo]

Very best wishes Pete!

[ramrod]

aaaarrrghh. that was TOO easy. lol..... i have three watches - a lucerne, a bulova and a seiko that have screw on backs that are NOT coming off. i'm almost ready to take a chisel to them. the lucerne nas indents on the case back but they are not deep enough to get a purchase on it. the other two - well, they have probably never been removed in their entire lives.

i'm almost ready to boil them.......well, not really.

Edited December 30, 2015 by ramrod

[bobm12]

Welcome back Dr! Belated Merry Christmas and non belated Happy New Year! May your wishes be true! Glad the problem was solved!

 

@ramrod: Check out the back of the Lucerne, it may be a press on regardless of the indentations. As for the others, use the Loctite method!

 

Cheers,

 

Bob

[ramrod]

HA HA.....you're good. lucerne was a snap on. it revealed an underwhelming movement - a one jewel winder.

the locktite method - please enlighten me.

[bobm12]

Sure. Just select a good sized nut and superglue it to the back of the watch. Then put the watch in a strong vise protecting the place where you are grabbing it and in such a way that the nut is accessible. Take a wrench and turn the nut and out will come the back attached to the nut. Then leave for quite a while in acetone so the nut will detach. If you do it right, there should not be any marks...Also, don't use epoxy, it is stronger and less sensitive to acetone. There is a small walkthrough I did using epoxy (not the glue I'm recommending) as an experiment and others have done it too here more or less officially...I think Geo has a good one on that one too.

[Geo]

Here's your thread on the subject Bob. http://www.watchrepairtalk.com/topic/1287-stubborn-screw-in-back-how-tomaybe/

[bobm12]

Thank you Geo! Much appreciated! :thumbsu:

[ramrod]

thank you, guys! what a great idea! i have that same epoxy also. o.k.....there's NO caseback that's too tough for me now.