Seiko 7A38 - by the numbers

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Forum Home > Bend it, Mend it - Mods & Wreckers > Botched ex-eBay (sub-30 Quid bargain) gold-tone 7A38-7190 - easily rescued ....

Seiko7A38
Site Owner
Posts: 9329

Subtitled: How not to release / remove a crown stem from a 7A38. 


I bought a gold-tone 7A38-7190 on a whim and a something of fuzzy photo gamble last week.

I didn't expect to win the auction, quite honestly. My maximum snipe bid was actually £29.67. :lol:


http://www.ebay.co.uk/itm/261595582188


The seller's description simply read:


Man Seiko quartz chronograph wrist watch in good condition for age it has one button cap missing other than that works fine any questions please message model number is 7a38-7190.


It arrived this morning. As I'd guessed from the seller's photos (have a look for yourself), the plating was in surprisingly good condition, apart from some tarnishing around the pushers .... and of course the crown was missing.


But the stem had been broken off short - too short to get a pair of needle-nose pliers on it, even with the movement out of the case.

So I did a quick strip down, in situ in watch the case: removing the backplate, PCB and green plastic '710' insulator spacer ....


Incidentally, the area of which corresponding to the stem was covered in gloop. A drop of 3-in-one oil to help free it up perhaps ? :lol:




Thereby allowing myself better access to the stem / setting and release lever linkage. This is what I found:




Not only was the stem bent out of alignment with the crown tube, but the botcher who'd had a go at it even managed to ding the tube !


With the release / setting lever now pulled out to the second 'click' postion ....




..... It becomes apparent how the crown tube acquired those dings. :roll:


Whoever had a go at it obviously had the movement out of the case (check the misaligned Tachymeter ring in the seller's photos).


Anyway, I got the old stem out with a little bit of fiddling and temporarily replaced it with gash one from my bits box:




The botched badly bent stem at bottom right.


September 23, 2014 at 6:05 AM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 9329

I was hoping to have got this 7A38-7190 back together yesterday afternoon, but other circumstances conspired against me. So I had to leave the final re-assembly till this morning. Although a stem would still just fit through the crown tube, as you can see from the above photo, the extreme inner end of it was quite badly distorted. I found a 1.3mm drill blank, which was almost a perfect fit, pushed that through from the outside then carefully worked it back to shape. I had a couple of NOS Seiko p/n 45M74NA1 crowns in my spares stock, but found another somewhat less worn used one, which seemed more in keeping with the overall used condition of the watch.


I carefully polished up the tarnished plating around the pusher housings, cleaned and greased the pushers, replaced the scratched crystal with a Sternkreuz p/n MSM310 and a popped in new Renata #394 battery (someone had fitted an under-sized Rayovac, which I binned immediately) and also new case-back gasket (as received, there wasn't one) .... so by lunchtime today it was on my wrist:



September 24, 2014 at 9:03 AM Flag Quote & Reply

donwatch
Member
Posts: 520

Nice Save , Paul :D

September 24, 2014 at 11:09 AM Flag Quote & Reply

Phil
Member
Posts: 148

You beat me on that one. :P Very nice restoration, I thought it had potential but I am known as a tight bugger.

September 24, 2014 at 1:19 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 9329

You mean you were the losing bidder who only bid £28.50 ? :| Serves you right for being such a cheapskate, then Phil. :P

In fact, I only bid with a view to using it as a potential 7A38 movement donor, but it seems a bit of a shame to break it up now. :/


September 24, 2014 at 2:44 PM Flag Quote & Reply

Phil
Member
Posts: 148

Yes that was me to be honest I'd forgotten about it, but while browsing I liked the look of the bracelet, I like it even more now :roll:


September 24, 2014 at 2:53 PM Flag Quote & Reply

Phil
Member
Posts: 148

No I tell a lie I have just checked my didn't wins (there are a lot :lol: ) I was an even cheaper skate at £27.

September 24, 2014 at 2:55 PM Flag Quote & Reply

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