Jump to content
  • Sign Up to reply and join the friendliest Watch Forum on the web. Stick around, get to 50 posts and gain access to your full profile and additional features such as a personal messaging system, chat room and the sales forum PLUS the chance to enter our regular giveaways.
Sir Alan

Seiko H556 5029 Restore

Recommended Posts

I like Seiko watches from the 1980's and have been restoring them (as best I can) for about 18 months now, learning as I go.

I thought I would write a few entries showing the restoration of a Seiko H556 5029 - referred to as a "Pre-Arnie".

This is a quartz movement, obviously driven by a battery.

The only downside of the battery, and its a big one, is that usually at some point in the watches life a battery has been left in the watch too long (we're talking 3+ years, sometimes much more), and when the owner comes to get a new battery fitted, the battery has leaked causing terminal damage.

At this point many watches simply go in a drawer, and then the bin.

However, luckily for us, many of these watches find their way onto ebay, or watch forums.

With ebay in particular, the famous listing words "needs new battery" can often mean "the watch is dead, and I'm selling it on knowing this. Good luck ....".

Still, for a determined tinkerer, this isn't the end of things, but merely the beginning.

I have previously restored a H556 5050 (referred to a a "Burke", from the film Aliens), and most recently a H558-5000 "Arnie", which I bought from KevKojak.

I'm starting to learn about the H55x movement (there are H556, H557 and H558 versions, all pretty much the same but with subtle but specific differences).

What is good, is that many of the parts are interchangeable, and working (or part working) watches with the H556 and H557 seem to be readily available, reasonably cheaply.

Also, some of the original Seiko parts are still available to buy - gaskets, crystals (though not always the exact part number).

This means it is possible to restore to working order a dead watch, and with some elbow grease, makle it look a lot smarter than when it arrived.

So, here is what I received in the post (from America).


(head only pictures as it came on a non original, horrible bracelet)

First impressions were that it was dirty, but in reasonable condition. Not battered, no signs of abuse and the bezel whilst worn is still very legible.

When I removed the horrible bracelet, I could see how dirty it was.



Oh well, I've seen lots of old watches like this, so I know what to expect ;-)

So, time to crack her open and see whats inside ............

Inside the case back (evidence of some blue / green substance ..... not good )


and the first look at the movement (with the green space block removed)


OK - so something has happened in here at some stage in its 30 year life.

Almost certainly a leaked battery.

We'll need to have a good look inside the movement to see what damage this has caused.

But first, lets get the case cleaned up ...........

Share this post

Link to post
Share on other sites

First the pushers need to come out:



they're both really gunged up. That's why there was virtually no travel in them - making the button functions not work.

There's more evidence of the green / blue deposit as well. It got around the case. Surprising (lucky) that the dial / hands weren't damaged by it.

To clean this all up I need to remove the bezel, then the crystal, the the crystal gasket, then the tachy ring (which is held in place by the gasket).

The tachy ring on these models is a pain, because it has the horizontal divider between the analogue and digital sections.

This makes pushing the crystal out very tricky, because you only have the width of the analogue section to push against (approx. 14mm), but the crystal is 29mm wide.

This isn't a good ratio, with all the pressure being applied in the localised small central area. On my 5050 and on the 5029 the crystal shattered when I was removing it. Luckily on the 5000 it didn't, but mainly because that crystal was much thicker (and thus stronger).

To be honest I expected this, and given I was going to replace it didn't mind.

But, be warned if you don't have a spare ready.

Bezel off:


and tachy ring out:


Share this post

Link to post
Share on other sites

Next its ultrasonic bath and toothbrush time.

This is always the fun bit (if rather messy).

Top side of case:


Bottom side:





Mmmmmmm - shiny :-)

Share this post

Link to post
Share on other sites

The pushers and their springs are always fiddly, but usually come up really nice (unless they're plated).


and the crown:


here you can see the star shaped end which sets the digital section of the watch:


Just like new.

Share this post

Link to post
Share on other sites

The case back also had that green / blue gunk:


so I cleaned it as best I could with the tweezers:


(I bought these tweezers 2nd hand, but they are a very good make and brilliant, being made of very hard steel).

Now, with everything cleaned up, its re-assembly time. Pushers back in, greasing them first with this:



Share this post

Link to post
Share on other sites

Then its back in with the tachy ring, carefully held in place with the crystal gasket.


Then its new crystal time. The correct Seiko part number is 305W22GN00

Unfortunately this is no longer available, so I picked the next nearest one (which to be honest is a bit of a leap in the dark until it arrives). I picked this one:


(next to it is the caseback gasket).

Fitting the crystal takes care to ensure its lying flat. With the tachy ring bar, its also important to keep the underside of the crystal as free from marks (fingerprints, dust etc) as possible as cleaning these off with the bar across is a real pain (trust me, I've been there).


Very nice.

Share this post

Link to post
Share on other sites

And then its back on with the bezel (greasing the inner gasket).



I just love the detail (which to be honest is hard to make out with the naked eye).

Here's the caseback with its new gasket:


and another shot of the case before I fitted the pushers.


Then next set of posts will cover the movement...........

Share this post

Link to post
Share on other sites

Great ! I love these sort of posts. Not a job I'd want to attempt but I admire those with the skill, the patience and the courage to undertake these restorations. Looking forward to the next part. Good work.

Share this post

Link to post
Share on other sites

With the case, pushers, bezel, crystal and crown nicely cleaned up, attention turned to the movement.

If you remember from one of the early photos, not only had that green gunk got into the case, pushers and caseback, it had also got onto the backplate of the movement itself.


I wasn't sure what to expect, but from previous experience I was expecting a mess inside.

Before I could work on the movement, I had to remove the hands and dial.

This is always a heart in mouth experience - if it goes wrong then you've got a damaged dial, damaged or ruined hands and something you have to look at.

That said, with the right tools and care it isn't anywhere near as difficult as you would think.

The first step is to line the three hands up, so that as best you can they stack up. This makes pulling them (with a presto style hand puller) safer.


But ...... on this particular model, the hands are particularly small (and therefore delicate) but worse, the hour hand sits almost flat against the dial. So close that to the naked eye it would appear to be touching.


this means getting underneath it, without damaging the dial is very tricky (especially with the plastic dial protector in place).

So, on this occasion I decided to take each hand off separately using hand levers. I'd not done this before but I felt it was the only option.

It was easier than I thought it would be. Phew!!



and hands:


And underneath ....................

Share this post

Link to post
Share on other sites

was a surprise:


it was very clean. I was expecting to see staining and worse.

Flipping the movement over I can now take it apart. First off is the battery retainer, then the battery itself.

Usually, when a battery has leaked the battery compartment is full of signs of the leak. But this one was clear, and very clean.

Then to remove the backplate, three screws hold this in place (along with the two screws that hold the battery retainer).


As well as the screws, there is a tab that clips onto the plastic movement block


Unclipping this lets the backplate come away, revealing another plate


this just lifts off, to reveal the PCB


Now I was really surprised that thus far everything was so clean.

The 4 previous H55x movements I have worked on were all very messy inside, all having suffered from battery leakage and damage.

Share this post

Link to post
Share on other sites

One thing I had spotted when I first opened the case up was that a small spring was missing. Here it is (from a previous movement)


When I re-assembled the movement I fitted this spring.

I wanted to check that the PCB was undamaged. This meant removing the LCD block. This is just a push fit, making electrical contact with two thin strips



The PCB (underneath) was nice and clean


Now, at this point there was no reason to further disassemble this movement. All I did was to oil the three bearings and put it all back together.

Share this post

Link to post
Share on other sites

I've just got the H558A Parts Catalogue so I can correctly name the parts of the movement.

In true Blue Peter fashion I had previously taken apart one of my donor movements, based on the H557.

Here's what a full strip down reveals.

First remove the red plastic insulator for the circuit (what I've been referring to as the PCB).


Apologies for the debris in this movement. This had suffered battery leakage, and you can see what a mess this makes.


then we remove the battery -ve connection


Then remove the switch lever cover



Share this post

Link to post
Share on other sites

then we remove this little fella


this is the setting switch lever.

As the crown rotates, the little star feet cause this lever to move left and right, and the little legs come into contact with the circuit, which registers this movement.

Then we remove the buzzer lead terminal (this is what that little spring sits on)


Then we remove the rotary step switch


by rotating this switch, the movement can be rate adjusted (trimmed). A really nice feature.

Next the coil block


these are very fragile. Its hard to see, but there is a ultra thin copper wire glued to each of the two contacts.

There's not much to go now.

This is the guide plate for winding stem


Share this post

Link to post
Share on other sites

Finally, the analogue section of the movement can be pressed out of the circuit block spacer (the black plastic block).


nice and self contained.

Which just leaves this


As I said, this block (and parts) are from a H557 movement.

It is worth noting that while most of the parts are the same between this and the H556 and H558 movements, there is one subtle but fundamental difference.

The top (LCD) section of the spacer block, and the LCD section itself are different shapes.

One the H557 it is more rectangular. On the H556 and H558 it is more rounded (or angular).

This means the H557 is not a drop in replacement movement for the H556 or H558 based watches.

However, as I hope I've shown, swapping parts around between these is very possible.

Share this post

Link to post
Share on other sites

Thanks for the feedback guys :thumbup:

My mains reasons for writing this up are:

1) the insides of these watches are amazing - they have to be seen

2) spreading knowledge - I started by reading posts like this

3) showing that it can be done by an average person

So, the watch is finished, everything works as it should (hands, LCD display, light and buzzer).

I haven't done anything to re-finish (or even polish) the case. I haven't started experimenting in this area yet and need to practice first.

Some final shots:






Share this post

Link to post
Share on other sites

I agreed to take a look at another of these for someone and did the stripdown this morning.

Here are a few pics of what I found inside. Evidence of a major battery leak and someone trying to clean things up.


damage to the PCB


and to the everywhere else


a real mess inside


Share this post

Link to post
Share on other sites

One of the major problems of battery acid damage on watches with plastic parts is that the plastic becomes brittle and cracks and even breaks away.

You might have noticed in the this picture:


the tiny plastic part lying on the gold battery terminal - thats one of the locating studs. Luckily its not essential but it does show you what happens (even before one starts to take the movement apart).

Here's another example (same movement) of damage:


and here is potentially the worst:


This watch was sent to me unable to adjust the digital time / date / alarm.

The cause was a combination of the gunge around this area (affecting conductivity) and also that pin above which I had to replace - the original was totally corroded.

I had thought the cleanup was going to be easy'ish but once I found what was inside I had to strip it completely, including dial and hands.

Once it was fully stripped I gave the plastic main plate an ultrasonic bath and very gently clean with the toothbrush.

It came up much better than I expected:




Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Create New...