Help! How do I open this Omega Cal. 620

[Gattaca]

Probably a stupid question but could  anyone help me with how to open an old ladies Omega cal.620? Pictures attached.

is it a snap on back or screw on? Because I just can’t seem to find a notch to get the back off it (if it is snap fitted), and I don’t think it’s a screw fit.

before I damage it I thought I’d come to the experts.

thanks

[watchweasol]

In a watch of this quality I would think its a screw back, so try the sticky ball. But checkout inbetween and at the root of the lugs for signs of previous entry.  Last chance saloon is the nut superglued on the back and a spanner to screw it off, super glue removed using acetone..   Also consider it may be a monobloc case using a split stem. In which case it comes out the front after removing the bezel and glass, and pulling out the split stem.   Need close ups of the bezel and case sides before being a little more exact.

[JohnR725]

2 hours ago, watchweasol said:

of previous entry.

usually with Popoff backs the watch companies will make something or in indent or something to give you a clue that that's with a knife goes. But not always and you have to be careful of prior high marks in other words somebody might've tried before you and did not succeed and you don't want to try in that spot.

I once saw a story of someone trying to open up a really nice railroad grade pocket watch the screw off back and observed Primark's and attempted to pry and made the marks much worse before grasping that screwed off.

 

2 hours ago, watchweasol said:

In which case it comes out the front after removing the bezel and glass, and pulling out the split stem.   Need close ups of the bezel and case sides before being a little more exact.

then I'm in agreement we need much better pictures of the case. Like for instance is there anything written on the back is a picture of the back of the case would be nice and much better side views because often times with omega they go out through the front but your pictures just can't tell.

[oldhippy]

As there are no indentations on the back cover showing like you normally get with screw on backs, I would say it is not a screw on. Look very carefully to see if a case knife could open it up, if you could take very clear close ups of the edge of the back we might be able to spot something. It might have a two piece stem in which case it will come out from the front, you would need to try and pull the button out with a little force to see if the stem parts, do not pull as if you are trying to break the thing, with some Omegas manly older types with a two piece stem, when the glass is remove and stem there is a clip built into the case that you move which will release the whole movement. 

[Gattaca]

14 hours ago, JohnR725 said:

usually with Popoff backs the watch companies will make something or in indent or something to give you a clue that that's with a knife goes. But not always and you have to be careful of prior high marks in other words somebody might've tried before you and did not succeed and you don't want to try in that spot.

I once saw a story of someone trying to open up a really nice railroad grade pocket watch the screw off back and observed Primark's and attempted to pry and made the marks much worse before grasping that screwed off.

 

then I'm in agreement we need much better pictures of the case. Like for instance is there anything written on the back is a picture of the back of the case would be nice and much better side views because often times with omega they go out through the front but your pictures just can't tell.

I’ll send some other pictures. Driving me crazy. 

[jdm]

22 hours ago, Gattaca said:

Because I just can’t seem to find a notch to get the back off it (if it is snap fitted), and I don’t think it’s a screw fit.

As said, a notch is not mandatory. One need proper tools and technique to open these, then a case press to close them back.

[valleyguy]

There is a video on Marks watch repair channel of him servicing an omega 620 ladies watch, the movement comes out of the front, but looks to have a snap on back.

 

 

Edited June 2, 2022 by valleyguy