# Fixing A Seiko 7548 700F



## Sir Alan (Sep 10, 2010)

I have been eagerly awaiting the arrival of my third Seiko 7548, a 7548-700F coming from the States.

I got worried on the 7th April when the USPS tracking status said it had been delivered on the 3rd April and I hadn't got it. 

Then I tracked it on the Royal Mail site and it said that it had arrived at their international facility on the 2nd and was shortly to be dispatched overseas.

Luckily I managed to talk to a very helpful person who agreed that the Royal Mail status was wrong and that actually the watch was being held with a customs charge and that I should have been notified. I said I hadn't, but if he could give me the amount due I could pay it and get the watch delivered. Unfortunately not. All he could offer was notifying the depot holding the watch to re-issue the note to me. Grrrrrr.

Anyway, the note arrived on Thursday (with the word COPY on it), I went on the web site and paid the charge, to be then given the option of a Saturday delivery or Monday. Given it was going to my work address I left this 'choice' blank.

And, on Friday the watch arrived 

It was listed as:

*Watch in non working condition for restoration/repair. We tryed a new battery but it will not start up, however the second hand twitches like it wants to run. Case, dial and crstal are very good with the exception of a very slight haze on the inside of the crystal, good rubber band and nice blue and red bezel.*

I'd also noticed from the listing picture that the hands were showing fairly serious lume rot, so I figured the insides were going to be pretty bad - either battery damage or rust.

Here's the first picture:



the second hand was 'twitching' very slightly.

I pulled the crown out to the second click to adjust the hands and felt a very weird resistance when rotating it - but the hands did move freely and the day/date change over was good.

So, what's lurking inside?

Taking the back off revealed this:



a surprisingly clean movement. The crown/stem was also very clean:



and the tube threads were in good condition:



as is the dial. The lume rot on the hands is 'interesting'


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## Sir Alan (Sep 10, 2010)

So, what's wrong?

Here's the lovely movement:



and no obvious signs. So, off with the circuit block:



wow - that's clean.



and nothing obviously wrong with the circuit either.

At this point I suspected either a faulty coil or circuit (I'd already tried a new battery!!).

So, I first swapped in a known working coil (from one of my 7546 movements) and the second hand kept twitching. Then I swapped in the circuit block itself. No difference.

OK, so its not an electrical fault - it must be mechanical.

The next thing I did was to look under the day wheel (I thought I could see some gunge under there) - but when I lifted this everything was pristine.

OK, so time to take the bridge off, and first signs of the problem:



that milky deposit on the underside of the bridge shouldn't be there. There was also evidence of a sticky substance (dried oil?) on the 3rd, 4th and 5th wheels. While I was in there, I lifted the center wheel bridge as well.



also signs on the center wheel.

Everything was cleaned (either in the ultrasonic cleaner or with rodico) and then it was reassembly time.


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## Sir Alan (Sep 10, 2010)

Getting the main bridge back on took a couple of attempts. I was just about to get it, then I realised I forgotten to fit the plastic second setting lever. Doh!!

After patiently nudging and directing things there was the wonderfully satisfying point when the last bearing was located and the bridge 'sat down'.



Then it was complete the rebuild and see if it worked. I was really pleased that once I'd lightly fitted a seconds hand and pushed the crown back in it sprang into life. :thumbup:

Next I took a look at the hands.



I had thought of re-luming them, but was worried that the lume wouldn't match the dial and I could easily end up making things much worse.

In the end I opted to clean the hands up as best I could:



there's a consistent patina which I like.

Next I stripped the case and cleaned it up, fitting a new yobokies crystal and re-greasing the bezel gasket, case back gasket and crown gasket.


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## Sir Alan (Sep 10, 2010)

And here it is on a Z22:





another save.


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## no8yogi (Oct 1, 2012)

Excellent as always sir!


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## digibloke (Nov 26, 2007)

I really like that you've kept it as original as possible - I often end up trying to make watches look like new and end up with too many after market parts. This looks ace as it is :thumbup:


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## johnbaz (Jan 30, 2005)

Hi

You did a grand job of getting that watch going again- Kudos :notworthy:

I have one too that doesn't work!! I bought it from a bootsale with the promise that 'It only needs a battery'!! I think they'd tried it and knew that it wouldn't go!!!

Here's a poor pic of it :yes:










Hmm, It's actually different to yours! I'm fairly sure it's a 7548 movement though :wink2:

John


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## Sir Alan (Sep 10, 2010)

I have been 'considering' what to do about the hands.

Other than leaving them as-is, the obvious option was to get them re-lumed and cleaned up.

My worry then was that they may not match the dial lume, and that if I was going to the trouble of getting the hands re-lumed, I really ought to get the dial done at the same time.

So I explored an option with a very highly recommended person to do this.

My only concern was whether I ought to do this, specifically to the dial. I don't have a problem with aged lume and patina.

In parallel to the above I started to investigate sourcing new hands. Original ones don't seem to be available (though I did see a listing for a seconds hand) and I wasn't really sure about aftermarket ones. I was thinking about yobokies (having already bought bezel inserts and crystals from Harold) and then I spotted a listing for a new SKX007 handset.

I'd read that these along with 6309 hands fit, I wasn't sure about the actual size but for about Â£8 it seemed to be a simple option to try. So, I bought them.

They arrived very carefully packed and this morning I took the original ones off and compared them in size to the SKX handset. To my eye they looked to be the same physical size and dimensions - excellent!!

And, they fitted perfectly:



after thinking about it, I've swapped back the original seconds hand. It has a more 'silvered' bottom half that matches the main hands better. Also, as the dial isn't black, it works better with this as well.


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## JWL940 (Jun 11, 2010)

Great write up and photo Sir Alan, thanks for taking the time to post it. A 7548 is one of my daily wears, it's nice to know a little more about it.


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## Littlelegs (Dec 4, 2011)

That looks great....) enjoy.


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