Seiko Quartz

Where it’s from

I bought this watch on eBay for $35.

What it looked like

The case is extremely beat up. I should have guessed that the eBay pictures didn’t show quite how damaged it was, but it’s extremely pitted in several spots. Furthermore, the crown is so worn, that it’s almost impossible to set the time. I was thinking of gifting this to my friend Jon, but I don’t think I could with the case this bad. I might try to find another case for it, maybe.

The dial is lovely though, and the movement runs and keeps good time (I let it go for a day or so).

How I restored it

Jan 30, 2026 3:20 PM

After opening the case, it seems the battery was held in with some tape!

I can see the movement is the Seiko 6530A movement. And, after reading a post in a forum about this movement, it seems you can actually date the watch based on the serial number. The case back has a serial number of 601616, which I believe means it was made in January, 1986. I also found a watchmaker’s mark in the case. I can’t really make out the letters, but the numbers say “86175” (I think). I’m not sure if that corresponds to a date or what, but someone cared enough to have this watch serviced, at some point!

I went ahead and ran the case through the ultrasonic, and honestly it doesn’t look half bad now. The pitting is still pretty visible, but the non-pitted areas look great, and all the verdigris is gone now. I think I will end up sending this to Jon after all.

When I popped the crystal out, it definitely chipped around the edge, due to the glue. I ordered a flat mineral crystal glass that should work, along with some UV glue. I’m not sure what I’m gonna do about the battery though, since it seems the tape was the only thing holding the battery in.

Feb 7, 2026 12:57 PM

Got the glue, glued in the crystal. Seems to look OK, but the glue definitely takes some practice. I definitely need to get a UV flashlight, as leaving the case out in the sunshine won’t be a workable solution 100% of the time, ha.

Feb 7, 2026 7:54 PM

The glue up went well, but unfortunately, the crowns I have do not fit this stem (0.9mm instead of 0.8mm). I definitely want to replace the crown on this, since the original has worn down to a stub.

Feb 13, 2026 5:19 PM

Ordered a crown, came today, installed it. I also replaced the case back gasket. I attempted to fix the battery terminals so that it’s not forcing the battery out immediately. While the battery sits in the movement better now, I think I may have munged something a little bit, because it wasn’t running at times. After closing it up though, it seems to be running now. I’ll just tell Jon that it’s old and junky, so it may not run. Anyways, here we are:

Feb 15, 2026 2:31 PM

Couldn’t leave well enough alone. I decided to at least just test the battery that was in there. On my multimeter, it read ~.9V, which I think means it was dying (it’s a 1.2V battery). I didn’t have the right size replacement battery, but I had one that was the right diameter but slightly too thick. Putting that in, it seems to run just fine. I ordered some replacement batteries, we’ll see if they do the trick. In the meantime I’ll keep an eye on this to see if it’s still running after a while.

Mar 28, 2026 1:57 PM

This had actually stopped running awhile ago, but I got caught up in restoring Dad’s Tag Heuer, and then this just kinda got put in the corner. I’m taking another look at it now though. I took a closer look at the jewels, and I think I can see some really dried out oil, so I’m going to try disassembling and cleaning this movement.

Things were pretty dirty! This is the first quartz movement I’ve worked on, and it’s very interesting. I feel like everything is much, much smaller than a typical mechanical movement. Maybe because there isn’t a balance wheel, so the gears can be as small as they can be to transfer just the impulse from the stepping rotor. The other interesting thing is that the stepping rotor has a big ol’ magnet on it, which I’m assuming is driven by the electric impulse from the coil (I actually had no idea how an analog quartz movement worked before this). All things considered though, this seems to be a pretty nice quartz movement, as it actually has 5 jeweled bearings. And it was pretty straightforward to disassemble and reassemble.

The dial side.
The movement side.
With the cover plate off.
With the train wheel bridge removed.
A close-up of the train.
With the oscillator and IC removed.
The stepping motor.
The movement, disassembled.
The stepping motor bridge.

I also think I’ve finally root-caused the issue with the movement stopping: The crown isn’t able to fully seat the movement in the “going” setting. It must be that the replacement crown I found isn’t letting the stem fully seat in the movement. I can tell this is the issue, since if I take the movement out of the case, I can get it to run just fine by pushing the crown in. I can’t just use a stem extender, because the ones I have are not the correct thread size, and would anyways make it too big to fit through the tube. So, I’ll need to source another stem from somewhere else. I also ended up filing the tube down just a little bit, just so that the crown could potentially seat all the way against the case.