G757 Battery Change and Buttons

[escapement]

Hi all,

My G757-5020 has run down.  It has had a history of being a bit of a battery chewer.  For a while I thought that putting it in the most economical display mode (ie avoiding use of the mini dial) would extend life when it was not being worn but I'm not so sure that works now.

Anyway, it is a fully working example.  The backlight is strong and clear, the LCD is perfect and all functions work as they should, including alarm tones etc.

I have some Seiko SR1120W 1.55V Silver Oxide batteries coming in the mail and will do a battery change myself with the following questions.

1) My smallest flat head jewelers driver is not small enough to undo the battery clamp - can someone point me to an online source of a set or driver which will do the job.  The one I have is adequate to prize open the case back but not quite enough to do the flat heads on the clamp.  I have had advice to magentise the driver and only remove one screw fully, the other only 75% as I can see it is super fiddly.

2) The gasket has also broken, can I source a standard round gasket of the right size and fit around the square back?

3) The buttons appear to have got a bit gummy.  How are they retained and can they be removed/cleaned/serviced?  I assume they are retained with o-rings but I've never stuffed around with this watch.

I'd love to hear some suggestions, advice or links to good resources for this job.  I am keen to return my octopussy to more general duties as it has been out of the wearing cycle for a couple of years now.


Cheers,
Will

[7s26b]

First I would download the tech pdf for the watch- available on the net.
If an original Seiko gasket is available, use one in preference to a universal one.
Try not to use screwdrivers to pry open cases, they can slip, scratch, render the seal unusable and if you're unlucky- kill the movement.
A small screwdriver is easily adapted by using a sharpening stone to narrow the blade and reduce diameter. Akiyose.com has good pictures of cell changes.
If it eats batteries, check the power consumption of the circuit.( tech pdf)

[cbrmike]

Here's the G757 Parts Catalog and Technical Manual (if this works out)

G757A.pdf (389.89 KB)

[camrok]

Glad to see someone else is a loves this particular beast. They are fickle and once the module starts to flake they are near impossible to find parts on.


Adrian-VTA has just finished doing an experimental repair on the left hand module the right is probably in the top 5 if my most prized watches.

As for the case back. I think the diameter of the generic Seiko diver case back gasket sits fairly well around it. But as for square I’m not sure what you will find. Adrian may be able to recommend something.
As for the buttons a standard digital pusher gasket should be easily obtained and fit. I’d recommend having a play with a less valuable digital if you were planning your own repair as the c clips and springs are very likely to fly across the room and be lost in the oblivion of the living room floor.

[escapement]

Thanks for the replies guys and suggestions.
The technical manual is a very good resource and I can see that those c clips are not something to trifle with!
I'll see how I go with the battery and sourcing a gasket that is about the right size - I won't be swimming with this unit that's for sure but finding something to protect it from the environment minimally is a high priority.
Maybe some sewing machine oil in the buttons from the outside will free them up a bit without requiring disassembly?

[edit]I note in the technical document the gasket is shown as round so I'll try to find a generic that is a decent fit.[/edit]

[Mr.Jones]

A while back, cousins UK still had these caseback gaskets in stock... Might be worth checking.

[Adrian-VTA]

You can just stretch an o ring around the caseback. The pushers are available.

[escapement]

Thanks all, a successful outcome.
New battery and after gently exercising the pushers they seemed to “come good”
Back to fully operational.
I’ll source an o ring now.

[escapement]

Doing some research on the caseback gasket for this watch now and I measured the broken one - it is a circumference just over 105mm but has no doubt stretched and probably was a "best-fit" one anyway.

When I look online at common circular sizes this looks like it might be the ø31mm ones... (31*π=97.38)

The part number I come up with is:

0E2930B04 (Caseback Gasket): 7813-80239, 7813-8039, G757-5000, G757-5010, G757-5020, G757-5030, G757-5040, H357-5110, H357-511A, H357-5120, H357-5140, H357-514A, H357-5150, H357-5160, H357-516A

or

G283-737 =  0E290BA11

cross referenced from ebay and some other sources like.

The second part is stated as not discontinued but the first is. However, neither of the second codes yield useful results in google for me.

COusins UK does supply caseback gaskets and once I know the sizing properly and know exactly what I'm after I'll see if I can order there - I also found some other modding sites which might help.

If anyone can confirm any of my findings or provide insight about the diameter/circumfrence and required thickness of the gasket I'm seeking I'd sure appreicate it.

I'll continue to document my research and results here as they may end up helping someone doing forum searches for this in future.

Cheers all!
Will

[Adrian-VTA]

OE290 = 29.00 x 0.85

You'd sub with 29.00 x 0.9 as you can't really buy 0.85 profile seals.

If you can't find one I'd have one here.

Nov 27, 2019 22:46:55 GMT -8 escapement said:

Doing some research on the caseback gasket for this watch now and I measured the broken one - it is a circumference just over 105mm but has no doubt stretched and probably was a "best-fit" one anyway.

When I look online at common circular sizes this looks like it might be the ø31mm ones... (31*π=97.38)

The part number I come up with is:

0E2930B04 (Caseback Gasket): 7813-80239, 7813-8039, G757-5000, G757-5010, G757-5020, G757-5030, G757-5040, H357-5110, H357-511A, H357-5120, H357-5140, H357-514A, H357-5150, H357-5160, H357-516A

or

G283-737 =  0E290BA11

cross referenced from ebay and some other sources like.

The second part is stated as not discontinued but the first is. However, neither of the second codes yield useful results in google for me.

COusins UK does supply caseback gaskets and once I know the sizing properly and know exactly what I'm after I'll see if I can order there - I also found some other modding sites which might help.

If anyone can confirm any of my findings or provide insight about the diameter/circumfrence and required thickness of the gasket I'm seeking I'd sure appreicate it.

I'll continue to document my research and results here as they may end up helping someone doing forum searches for this in future.

Cheers all!
Will

[escapement]

Hi Adrian, I would like to discuss with you the possibility of obtaining a suitable O Ring.

I'm not getting anywhere with my investigations and I've run into some problems that I think are related to this.

I'll be starting a new thread to discuss properly.

Thanks for the offer!

best,
Will