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Discussion Starter · #1 ·
Hello all,
After years of searching, I finally obtained a 7a28-7020. The "bond" version. It was untested which I assumed meant totally busted but to my surprise it works...almost. I installed a new battery here is what happens:
Hour and minute working. Keeping time
Second sub at 6 is working. Hacks when crown is pulled
Chrono second hand (large hand) works when top right button is pressed
Split time, top left button seems to work.

Now to the problems. When the crown is pulled to the first position, all the subs reset. Or they go through the motion. The chrono resets at 31 seconds. No way to adjust. It seems the reset button (bottom right button) isn't working. The others buttons work as they should. With the crown back in the chrono works when you stop and start it, just no way to reset. The reset button does not seem to do anything.

Anyone know if this is a common problem...with an easy fix:) super excited to have one of these finally.

Cheers!


Sent from my iPad using Tapatalk
 

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and Cognoscente ... 15J Quartz Chrono's
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It seems the reset button (bottom right button) isn't working. The others buttons work as they should. With the crown back in the chrono works when you stop and start it, just no way to reset. The reset button does not seem to do anything.

Anyone know if this is a common problem...with an easy fix:) super excited to have one of these finally.

Cheers!
Possibly a rusted switch lever (and/or corroded corresponding contact post) behind the 4 o'clock pusher.
Quite an easy fix (if that's what's actually causing the problem).
You need to remove the movement back-plate (7 fixing screws), the PCB and then the green plastic spacer to check their condition.
 

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The 7A28/38 series are pretty awful for pushers either getting stuck from dirt or letting water in causing the non-stainless lever to rust.

Could also be the seal has broken up or the pusher tube has taken a hit.

Should be fairly easy to diagnose but watch those pusher clips, they fly off never to be seen again so cover the back with clear plastic.
 

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and Cognoscente ... 15J Quartz Chrono's
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The 7A28/38 series are pretty awful for pushers either getting stuck from dirt or letting water in causing the non-stainless lever to rust.

Could also be the seal has broken up or the pusher tube has taken a hit.

Should be fairly easy to diagnose but watch those pusher clips, they fly off never to be seen again so cover the back with clear plastic.
Only through neglect / ignorance.

How do you propose the OP checks the condition of the switch lever(s) with the back covered by clear plastic ? :confused:

If you read what I suggested in my previous post, he doesn't actually need to remove the pushers (nor their circlips).
Checking condition of the switch levers can be done quite easily with the movement still in situ in the watch case.
 

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Discussion Starter · #7 ·
Wow, thanks for all the info. I'll post pix tomorrow and see what I come up with.

Something else I noticed, there is a rattle inside the case. I believe it to be the chapter/chrono ring not being held in enough. I unscrewed the case back to install battery but didn't full tighten. Need to look at a diagram to be sure I'm not missing a spacer or something.
 

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Only through neglect / ignorance.

How do you propose the OP checks the condition of the switch lever(s) with the back covered by clear plastic ? :confused:

If you read what I suggested in my previous post, he doesn't actually need to remove the pushers (nor their circlips). Checking condition of the switch levers can be done quite easily with the movement still in situ in the watch case.
Huh? What a totally unnecessary and offensive rant based on your misunderstanding of what I wrote :eek:

I was merely describing (based on personal experience) some of the very common issues with the pushers on these watches. Until 66cooper does some more investigation nobody can say exactly what's wrong, as you admitted previously. Restricted travel of the pusher by dirt, a broken up seal or a dent to the tube could also be a cause.

Covering the back of the watch with clear plastic is simply a method of preventing the tiny PUSHER CLIPS (that prevent the pushers from sliding out, nothing to do with the movement levers) from getting lost when removing.

Also it would be perfectly possible to check the condition and function of the switch levers without dismantling the movement as you suggested.
 

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and Cognoscente ... 15J Quartz Chrono's
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Possibly a rusted switch lever (and/or corroded corresponding contact post) behind the 4 o'clock pusher.
Quite an easy fix (if that's what's actually causing the problem).
You need to remove the movement back-plate (7 fixing screws), the PCB and then the green plastic spacer to check their condition.
PS - If you go this route, be careful of (not) losing the tiny gold plated rotary step switch, which sits atop a post above the green plastic spacer. They are more likely to ping off into space than the pusher circlips. :p
 

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The foregoing obviously based on your very limited personal experience of these watches. :rolleyes:
Wow what a way to sound like a complete ****.

Great for being helpful but don't shoot people down for being just as helpful as you with some very considered and sensible advice given.

You might think you are a 7a28 god but many many people here are capable of working on these and should be able to give advice without being insulted.
 

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Discussion Starter · #12 ·
Hate for this post to cause ill will guys. We All love these great watches. Every opinion is worth reading.

So, I might be a little slow with things as I have just welcomed a new addition to our family. A boy to compliment my daughter. Hopefully both will be watch collectors like their dad:) actually bought this watch while in the hospital trying to kill time before we had him. I think this one will HAVE to be his at some point.

Ok, well I took a look inside again. With the movement removed, I was able to push the reset pusher in to activate it. Even that way, it wasn't perfect. Very tricky to get it to work. I did managed to get the chrono hand reset back to zero which is GREAT! Obviously, I have an issue with the reset pusher/contacts as it does not work when installed in watch. Does that give you guys more clues as to the exact problem?

Any ideas on the rattling chapter ring?

I have some watch repair experience but I would consider myself a novice, especially with quartz movements. If I were to have this watch serviced, any advise as to where, and how much I should expect to pay? The only other problem is that the crystal is knackered and I would like to replace. Is sapphire and option? Any thoughts would be great
 

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Hi, I've worked on quite a few 7A28's, 7A38's and 7A48's.

Judging by what you've said, I'd say that the pushers are clogged up with dirt which is preventing them travelling far enough to make contact with the switch lever in the movement. This is really common on watches of this age. It's scary how much grunge builds up.

Here's a picture from a 7A38-705A




see the pusher on the left - this is by no means the worst I've seen. What you also get is the same grunge in the case (in and around the cup the pusher fits into). Again, by no means the worst.




Here is the case after I've completely cleaned it:




The combination stops the pusher travelling the final 1mm or so and so prevents it making electrical contact. The pusher then appears to not work.

To test this theory, remove the movement from the case (to do this you'll need to release and remove the crown/stem) and then re-fit the crown/stem. The movement will start working when the crown/stem is fitted.

Be very careful not to touch the dial or the hands.

Then very carefully activate each switch in turn (I use a 2.5mm screwdriver).

If each switch works then you know its simply the pushers.

If any of the switches don't work, you'll need to investigate what the fault is.

Irrespective of the above I would recommend that you remove all 3 pushers, completely clean them and re-grease the gaskets (better yet fit new gaskets).

The only tricky part of this is removing the tiny c-clip that holds the pusher in place. With the right tool it is actually easy (I put a small amount of silicon grease on the c-clip to stop it pinging off). Without a suitable tool its next to impossible. I use this:




the v groove is essential as it allows you to apply pressure to both open ends of the c-clip evenly.

If a switch lever doesn't operate when pressed (out of the case) there is the possibility of rust on the switch lever. Here is an example:




there will almost always be evidence and signs of this without having to open the movement up. Look for rust particles in the case, or on the edge of the movement.




Fitting a new crystal is easy. The correct crystal is Seiko part number 320W40GN00.

However this is obsolete so finding this exact part might be difficult. There are suitable other crystals (e.g. Sternkreuz XMF 320.855 etc) that will work nicely.

Hope the above helps.
 

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Discussion Starter · #15 ·
That helps immensely, thanks!
Funny thing happened...well not so funny but anyway. My 4-year old happen to knock the watch from my table, straight onto the tile floor. OUCH!!! I had to keep my cool. She knows that watches are delicate in that way and was very upset it happened. Good kid. I assured her it would be ok and to just be more careful. Fathering done with, I inspected the watch and to my surprise, the rest pusher now works!! Its not perfect but it works. Crazy. I actually had to tell my daughter so she would feel better.

Now, I think that cleaning the pushers is a great idea. The watch was very grimy with lots of "DNA" on it. I had to soak the bracelet and really give it a good scrub as well as the watch case. I'd image the pushers are pretty gross as well.

I will have to buy a new crystal and then have my watch guy replace it as well as all gaskets at the same time. Maybe look at the reset pusher contact point to be sure its clear but there is no rust that I noticed.

So, last problem then, the rattling chapter ring??? Whats the deal with these? From the back, there are notches that line it up with the dial but what keeps it from moving around? Pressure from the movement? I wonder if I am missing something? What keeps the movement in place once the case back is removed? Once I removed the case back, I removed the crown and the movement was able to be removed.
 

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Discussion Starter · #16 ·
Quick update:

I didnt want to wait for my watchsmith so I dived in. I removed the movement and the reset pusher. Sure enough, filled with junk. Cleaned it out as well as I could and, not having grease as I am at work, I just a tiny bit of chapstick. Yes, lip balm!! The pusher was still a little sticky and the lip balm did the trick to smooth things out. It now works BRILLIANTLY!!!! Thank you all SOOOOOO much.

Rest assured, this watch is heading to the spa for a cleaning, all new seals, and a new crystal. obviously, with proper greased gaskets. hahaha!
 

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resetting to zero

it can be a simple fix. my 7a28-6000 guigiaro was fine for a while,
then it started resetting to 9 seconds for no apparent reason, which
is really annoying. in this case, i pulled the 8-oclock crown out one notch,
then manually advanced the second hand 51 clicks to "12" by pushing the
four o'clock pusher, each push advances the hand one second...then pushed the
crown back in. voila, the watch resets to "12" perfectly now...
 

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haha,

i just got a 7a28-7090 in the mail, and it was not
resetting to "12", so i came here to follow my own
advice, as i'd forgotten the technique. this watch is
supposed to have just been serviced, so i hope
it's not a gunk issue, it looks like manually resetting
it as directed above has fixed the problem...
 
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