7606A/42 799 RO

[Gustavo]

Greetings Guys from Puerto Rico: 

I'm new to the forum and also to the watch community,  

I love watches since childhood but now I am introducing to this all new repair aspect of it. 

I am on need for help since I have been reserching about 2 months ago from this particular caliber (7606A/42 799 RO) and with not sucess of find anything about it. 

The 7606A its in the balance cock printed and on the dial its marked as a 42 799 RO. 

If any one out there on the community has any information or the repair manual of it would be very helpful to me since a have a complete watch but in pieces. Just looking down as my first project ot get it back running if its possible. 

 

Thanks, 

 

 

Gustavo A. 

[Graziano]

Hi there I haven't got a manual but maybe this can help a bit 

The 7606A is a 23 jewel automatic, with day/date complications and a quickset date feature, operated using a push button located at 3 o’clock position to the crown’s 4 o’clock.  It is this feature that marks this one as out of the ordinary and makes the watch just that bit more distinctive than many of the other Seiko dress watches from this period.  The case has considerable presence, with square, bold lugs, a very attractive dial/handset, a wide indexed chapter ring and a very large acrylic crystal.  The one I found looked presentable but with an inoperable day complication, stuck half-way between Wednesday and Thursday and a sticky half-functioning date quickset.  The case back on this one is a press-fit, snap-on type, requiring a proper tool with a thin but blunt blade to prise it open without risk of damage.  Once open, we can see what lurks beneath:

Clearly, pretty grubby in there, some rust, and a foreign body sitting bold as you like on the rotor, which itself appears to be coming apart at the seams.  A better view of the stray part suggests a badly rusted screw, its origin not yet clear but it looks like one of the dial retaining screws.

So, with the movement extracted from the case, which required destruction of the case back gasket, and the rotor removed, we can take in its general state:

All we get from this view is confirmation that its been a while since its last service, a suggestion of rust in the autowinding bearings (centre) but other than that it all looks pretty standard stuff.  With the autowinding mechanism off we see that the underlying architecture features not the single train bridge of many of the 6 series movements I’ve worked on before but separate train and barrel bridges:

This seems like a good point to flip it over and take a look at the calendar side:

On this movement, the day and day change over more or less in tandem around midnight (day first, then date) in contrast to many of the later Seiko movements I’ve worked on which seem to complete the date changeover before the day gets its act together.  We’ll see shortly how that works.  Off with the day disk:

taking the hour wheel and film washer with it.  Note the angry looking star of teeth  sitting on its underside.  With the hour wheel back in place we can take a proper look under the hood at the calendar mechanism and see how that simultaneous day/date change works.

The key to the day/date changeover is the date driving wheel on which sits the date finger and day finger (indicated above).  The date driving wheel is itself driven by the hour wheel (centre), two revolutions of which turns the day driving wheel through 360 degrees.  As it turns, the day finger engages with the teeth on the underside of the day wheel (see preceding photo) slowly turning it clockwise whilst the day jumper slots into position between two of the teeth, ensuring that the day aligns correctly with the date, once that has changed too, and holding it in position until the next changeover.   Meanwhile, the date finger, which points in the opposite direction, starts to engage with the teeth on inner diameter of the date disk, turning it anticlockwise, with the sprung date jumper then ensuring it moves exactly one date forward.    Note that in the photo above the day and date fingers in the photo above are aligned more or less at mid-day rather than midnight and so would be half way through their journey to the next changeover.

Continuing to dismantle the movement, but still focussing for the moment on the day driving wheel, we get a good idea just how complex and nicely engineered these older movements are.  Removing the solid day finger, we get a look at the separate date finger which is sprung and can move about a pivot sitting at its elbow, allowing a more progressive day changeover with the force gradually building as the wheel advances until the resistance provided by the date jumper is overcome.  In operation the day starts to change a little before any action is perceptable from the date.

The finger is easily removable for cleaning:

and we see the natural curl of the spring.  With pretty much everything else removed, we pause for a moment to look at the date quickset mechanism, operated by that cool little button at 3 on the case.

The key parts here are the date corrector lever, which moves inboard when the 3 o’clock button is depressed.  This lever in turn exerts a force on a lip at the edge of the date corrector itself which moves against one of the teeth on the inner circumference of the date disk.  You can probably see better how this works from this figure taken from the 7606A technical manual:

A view of the now near naked calendar side of the mainplate shows the date corrector and the spring which provides the resistance to the button and returns it to its rest position once the date has been changed (or corrected).

One parting shot from this side shows two of the Diafix jewel holes with springs and cap jewels removed (an operation considerably fiddlier than for Diashock jewels, which themselves take some practice dissembling and reassembling).  The two Diafixes are used as bearings for the third wheel and escape wheel.

Stripping the other side of the movement was uneventful and after a thorough clean we can start to put it all back together again, paying attention to proper application of the correct amount (by my reckoning anyway*) of the correct lubricants in the proper places.  Here’s the calendar side coming back together, Diafixes refitted

and back to the other side, with most of the fixtures and fittings back in place:

Note that only the escape wheel merits a Diafix on the third wheel bridge, the third wheel pivot making do with an ordinary jeweled bearing.  study this write up and good luck .

 

Edited March 22, 2020 by Graziano

[oldhippy]

Thank you for your introduction and welcome to this friendly forum.

[jdm]

3 hours ago, Gustavo said:

If any one out there on the community has any information or the repair manual of it would be very helpful to me since a have a complete watch but in pieces. Just looking down as my first project ot get it back running if its possible. 

Is this the first watch that you have to re-assembly? I think that if you do the same on another (of small value) that is complete and  even has a diagram, you will find that mist are very similar, oiling points are alwasys the same, etc.
Also remember, to help other help you, always post clear pictures of the current problem.
 

[steve855]

 

 

 

Graziano,

 

 

You should probably give credit, this appears to be lifted directly from the excellent blog "Adventures in Amateur Watch Fettling".

 

[/url]https://adventuresinamateurwatchfettling.com/2012/07/10/1964-and-all-that-birth-year-projects-part-i/

 

Unless it's your blog, in which case never mind.

 

 

 

[VWatchie]

 

2 hours ago, Graziano said:

Hi there I haven't got a manual but maybe this can help a bit 

@Graziano Did you just produce that or did you copy it from somewhere? Providing a link (again) would be much appreciated!

[Graziano]

1 minute ago, VWatchie said:

 

@Graziano Did you just produce that or did you copy it from somewhere? Providing a link (again) would be much appreciated!

The Link is in the post above ,thank you

[VWatchie]

11 minutes ago, Graziano said:

The Link is in the post above ,thank you

Thanks!

As a general rule I always prefer links to the original sources. The simple reason being that it makes it so much easier to find complete content and related information. Also, I agree with @steve855 that we should give credit to the originator of the content.

BTW, the link in steve855's post did work, so here goes: https://adventuresinamateurwatchfettling.com/2012/07/10/1964-and-all-that-birth-year-projects-part-i/

Edited March 22, 2020 by VWatchie

[Graziano]

1 minute ago, VWatchie said:

Thanks!

As a general rule I always prefer links to the original sources. The simple reason being that it makes it so much easier to find complete content and related information. Also, I agree with @steve855 that we should give credit to the originator of the content.

My apologies and I will oblige I was just taking out the relevant information  so as to not confuse the op,Thanks Mr VWatchie

[steve855]

I was not trying to be critical, the information was relevant and I'm sure helpful to the OP.
It was just a reminder that it's considered good form to give credit to the creator of that information.

Steve

Sent from my SM-G930V using Tapatalk

[Gustavo]

Hello again guys, 

Thanks for the helpful info to all of you. 

Yesterday I also found this page, 

https://watchguy.co.uk/cgi-bin/library?action=show_photos&wat_id=2154

with some helpful photos to keep on the trajectory of the watch. 

Also thank you to @Graziano and @steve855 to post the link and also the info on the page. 

Attach I am uploading the actual situation of the watch and on what condition I the watch was giving to me. The previous owner friend of my grandfather gave it to me since he take it all apart and never was able to mount it again back. 

Thanks all for the help and would be posting more pic of it and document the process.

 

 

IMG_2402.HEIC

[VWatchie]

On 3/22/2020 at 12:00 PM, Graziano said:

My apologies and I will oblige I was just taking out the relevant information  so as to not confuse the op,Thanks Mr VWatchie

I understand and no worries Mr. @Graziano! 

It's very generous of you to be "taking out the relevant information". Just include a link as well, and we'll all be happy! 

Edited March 23, 2020 by VWatchie

[jdm]

On 3/22/2020 at 8:03 PM, Gustavo said:

The previous owner friend of my grandfather gave it to me since he take it all apart and never was able to mount it again back. 

Which is a very normal when someone with zero knowledge thinks to know better and goes to attack his nice watch.

To be blunt you risk to end in the same situation, with slim chances of having it run good again, or run at all.

The only way to increase chances of success is that you get proper tools and practice on so nothing else before.

[Gustavo]

@jdm Completely understand your point! 

I already order a small kit to begin the trajectory and learn along the way. But clearly will continue learning and sharing my expercience with all in the forum. 

Have a great night, 

 

Be safe

From PR