Seiko 7A38 - by the numbers

Subtitle

Forums

Post Reply
Forum Home > 7Txx General Discussion Area > Seiko 7T36-6A29 - Broken or am I not doing this right?

seiko7f38
Member
Posts: 2

So I recently acquired a Seiko 7T36-6A29.  So excited was I to receive it that as soon as I opened the package I went about setting the correct time.  The problem - once the crown was pushed back in the watch didn't seem to work.  I can't believe how stupid I was to not check if it was working before I set the time.  I didn't even look to see if the second hand was ticking or not !


The thing is the stopwatch/tachymeter, date and alarm all work fine but not the main time dial.  Whenever I pull out the crown to set the time and push back the crown, the second hand (left sub dial) will work for roughly the length of time the crown was pulled out for before then stopping.  Is there a trick to setting the time on this watch or is it broken?  I have looked everywhere for a user manual but can't find one that shows how to use the different functions on the watch and therefore how to set the time.  I guessed (stupidly) it would be like my other Seikos but I'm not sure if this is the case.


Can anyone help me out with this?  I'm praying that there is some simple trick to getting this watch going but fearing the worst.

Thanks,


October 29, 2014 at 6:15 PM Flag Quote & Reply

garacs1
Member
Posts: 508

Hi there, sorry for late reply. When changing the battery of any 7Txx series Seiko, you should always reset the movement. This is done shorting the AC point in the back of the movement (it is clearly marked on the back plate shield) and the positive of the battery. You can use a pair of steel tweezers, or a fine metallic clip. Careful not to insert the tweezers or the clip inside the wrong hole. I usually find that this works when the main crown is pulled out to the second position (full out). Keep the short in place for at least 5 seconds. This should reset completely the movement. Proceed then to set the hour as usual: pull the main crown out to the second position and turn it to set the correct hour and minute. While at it, press the pushers top right and top left to set the chronograph minute and seconds respectively to 12hours (rest position). To set the hour, press full in the main crown.


The small dial at 6 o'clock is the dual time and alarm dial. To set the dual time, pull the small crown out to the second position (fully out), and set the time accordingly. To save the set hour, press the small crown fully in. To set the alarm time, pull the second crown only one position out, and press the pusher bottom left. Holding it pressed will make the hands move faster. Once set the desired alarm time, press the crown back in. To engage the alarm, simply pull the second crown out again to the first position. To stop the alarm from ringing, either press one of the 3 pushers, or press the crown back fully in.


Last but not least: date and moonphase setting...

To set the date, simply oull out the first crown out to the first position, and turn the crown clockwise (as you would do to set the hour hands). To set the moonphase, turn the hand counterclockwise. Once set, press the crown fully back in.


These are the instructions on how to operate the Seiko 7T36-xxxx series watch. If the watch does not work properly after a complete reset and hour set, then it either has a battery problem (did you check if the battery is new? Is it the correct battery?), a circuit board malfunction, or a mechanical problem. Opening the Seiko 7Txx series movements is not a job for the faint hearted, since the gears are all made of plastic, and reclosing it is a pain. Replacing the circuit board is far easier, but the problem is findung one, since this watch series is not in production anymore, and the few to be found on ebay cost an arm and a leg. You'd be better off finding a battered watch with working movement and simply swap it into the watch you bought. Some 7Txx are still to be found, just look on the usual places and they appear sometimes with low buying prices. Patience is a must...

--

My personal Blog: www.onlyvintagewatches.com/blog

November 1, 2014 at 9:19 AM Flag Quote & Reply

seiko7f38
Member
Posts: 2

Thanks very much for your reply.

I had a look at the ebay photos and it confirmed that the main time dials were not working when I received it as all the photos show the second hand and minute and hour hand in the same position despite the photos being taken at different times (and I can see that the crown has not been pulled out in the photos.)

I really want to get the watch fixed and I dont think it is a problem with the plastic gears being broken as the time function does work momentarily when the crown is pulled out and then pushed back in but then stops again.  The battery is fine though so am not sure what the issue is.

I read your blog previously when I tried to fix another Seiko and realise that replacing the movement is beyond my skills.


November 8, 2014 at 1:51 PM Flag Quote & Reply

garacs1
Member
Posts: 508

Actually replacing the movement for a working one is the easiest solution to your problem, I think. As per the broken gears, being them of plastic they can only have a few teeth broken or worn out, thus making the movement temporarily work in certain conditions (pulling out the crown, for example). Be aware that the main time gears and the secondary time gears are separated, so if the main time is not working, the secondary may still perfectly work, and vice versa.

--

My personal Blog: www.onlyvintagewatches.com/blog

November 14, 2014 at 9:20 AM Flag Quote & Reply

garacs1
Member
Posts: 508

I was also thinking another thing: can you properly set the moonphase, and the date? If not, then maybe something is impeding their movement, which then blocks the main time indication (the date and moonphase complications are directly connected to the main time gear.

--

My personal Blog: www.onlyvintagewatches.com/blog

November 14, 2014 at 9:23 AM Flag Quote & Reply

You must login to post.