Seiko 7A38 - by the numbers

Forums

Post Reply
Forum Home > Parts Info, Tech Tips and Tinkering > Battery Eating 7A38

donwatch
Member
Posts: 504

:mad:   Seiko 7A38 “Battery Eating Monster” First off, I will state that this watch has ALWAYS FUNCTIONED PERFECTLY !! Except---> It has gone through 5 battery's in the last month ! It is a watch off E bay from an Australian seller. The first battery was off my work bench and lasted two days. At this time I did not have any fresh 394's and I again installed a used battery. The second lasted 2 days again, OK what gives ? I tore down and found that there were some corrosion on the PCB near the usual place next to the battery. I have several used spare PCB's and selected one. Back together, the watch is now working well in all respects. I installed a fresh battery this time around, and the ran for 5 days before the battery went dead. Whats up with this ?? So I got into a movement that has been running on my bench for the last 6 months and robbed the PCB out of it. Installed a fresh battery and the watch ran for about 5 days before killing the battery! Ok maybe I'll replace the coil that runs the time only because during the last go around I only started the chronograph a couple of times. I tore it down again and robbed the coil out of that good running Mvt... I am getting good at replacing those 7 screws by now ! New coil in, fresh battery. Dead in 5 days......Now WHAT ? Is it friction on the train ?    :/ :mad:                                                                                                                                            

December 15, 2014 at 9:19 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 8884

I remember when that 7A28-725A first appeared on eBay, Don - I posted about it in the Finding Hidden 7Axx Gems thread;)


Originally posted by myself on August 19, 2013 at 8:24 AM:


This cosmetically nice-looking condition, but non-runner 7A38-725A offered in a job lot by a US eBay seller wasn't very difficult to spot:


http://www.ebay.co.uk/itm/300948651355



Obtained from various estate sales is this lot of 3 vintage Seiko watches. All are Quartz. When batteries were installed none worked. Fix or use for parts. One is a SEIKO chronograph with a dk gray/black and gold tone band and case which cosmetically is in very good condition. Case is signed 7A38-725A. It does not look like this watch was worn much. It measures approximately 40 mm in diameter and 42 mm lug to lug. The middle watch has an orange dial and a silicone orange ....

As I do not know the history of these watches, they are sold AS IS and are AS FOUND. Shipping in the lower 48 states is $6.50. International requires registered mail. International bidders email for shipping costs to your country before bidding ....




The 7A38-725A certainly looked like it might make a good fixer-upper. For the best part of last week, I was the only bidder. Not that I needed another one, but before I went to bed last night, thinking to myself 'whatever', I set up an automated bid on auctionsniper, as the auction was scheduled to end at 4:00am BST, this morning. No chance ! A few others had obviously seen it too. Three snipe bids came in the last 6 seconds. The third lowest was marginally higher than mine, so my snipe bid didn't even register. C'est la vie ....


December 16, 2014 at 4:45 AM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 8884

Here's a bit more history - posted by Stuart Lennard in his My 7A collection from Down Under thread.


Originally posted by ginny on October 8, 2013 at 8:54 AM:


Thats a bit of history I did not know. This 7A38-725A came from a lot of 3 for repair, still has the case back sticker attached. Has a small scratch on the crystal but overall in pretty top condition. The seller claimed he fitted a new battery, but it did not work. Well he must have installed a dead battery , when I fitted one , everything worked as it should. :)


December 16, 2014 at 4:57 AM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 8884

Stuart didn't actually say how long it worked for though. :lol:


Nor did he mention anything about it in his eBay listing description: http://www.ebay.com/itm/121476488814

 

SEIKO 7A38-725A IN GREAT CONDITION. 

ONLY ONE FINE SCRATCH ON CRYSTAL, A COUPLE OF VERY FINE SCRATCHES ON CASEBACK AND ON ONE GOLD LINK ON BRACELET THERE IS A VERY SMALL WEAR MARK. 

APART FROM THIS THE SEIKO PRESENTS AS NEW. 

ALL FUNCTIONS WORK AS THEY SHOULD.


Perhaps this was the gotcher:

SORRY BUT DUE TO POSTAGE REGULATIONS I CANNOT SHIP WITH BATTERY.


Anyway .... what do you expect for $69 ? :P



December 16, 2014 at 4:58 AM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 8884

But seriously, Don ....

Have you checked the current consumption ? :| See page 11 of the 7A28A Technical Guide.


December 16, 2014 at 6:05 AM Flag Quote & Reply

donwatch
Member
Posts: 504

I have not checked with a meter, Paul.  But I would assume it is drawing too much current.  But where is it leaking?  Something is grounding it but not enough to keep it from working for 5 days :( and remember that last PC board came out of a movement that had been running for 6 months ( same battery ) :P   I am going to pull the coils out of the chrono functions, AND get a strong loupe to look for something ( sliver of metal :/ ;) bleeding off current. 

December 16, 2014 at 11:23 AM Flag Quote & Reply

donwatch
Member
Posts: 504

I think I have solved the problem ;)  ------> a doner watch from an Italian ebay seller with only one ( 1 ) feedback :roll:  He says it is untested--If it runs correctly I will swap the movement into the one I have with the battery eating problen.. I will work on the battery eater at a later date  :/  In any case I can use at least three links from the band. :D


February 17, 2015 at 2:34 PM Flag Quote & Reply

donwatch
Member
Posts: 504

The Italian seller with one feedback sent the watch Registered and well packaged !   I installed a Sony 394 battery and all functions worked perfectly :D   I also took a deep breath and removed the scratched crystal from my 725A and replaced it with a new one from Esslinger.com  -----Went smooth 8)  Also, I was able , with much fiddling get three links fitted from the doner band  :D    Can I  dare to say,  this is a RARE model ?   I am pleased with the result!  Now on to the battery eating movement---some rainy day  :/  :P 

     

February 23, 2015 at 12:14 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 8884

Can I dare to say, this is a RARE model ?


Nah - don't think so, Don. :P



February 23, 2015 at 12:32 PM Flag Quote & Reply

donwatch
Member
Posts: 504

OK I'll take the one on the right ;)   You can always replace it :roll:   I know you are proud of that photo of the three, do you still have three ?

February 23, 2015 at 12:57 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 8884

No, the one on the right was sold a couple of years back, Don.

As you're following my other eBay ID, you'll probably already have seen it in my feedback as one of the last items I sold ....

Classic 1988 SEIKO 7A38-725A Quartz Chronograph *RARE* (#230542366381) Rare ? Nah don't believe a word of it. :lol:

February 23, 2015 at 1:23 PM Flag Quote & Reply

You must login to post.