Seiko AGS 7M22A

[HectorLooi]

I just restored this watch yesterday which belonged to my father. I believe it's the precursor of the Seiko Kinetic. I think the AGS is short for Automatic Generator System.

It was a troublesome watch and my father had it repaired several times by the local Seiko repair centre several times. I believe the PCB was changed a couple of times and the generator once. When the gold capacitor was phased out and a rechargeable battery was put in, the battery eventually leaked and damaged the insides. So it was in my dad's drawer for decades.

I took it out several times to attempt fixing it. I washed the PCB in distilled water to remove all traces of battery juice then put a new Seiko capacitor in. It worked for a few days then stopped. That was a couple of years ago.  Recently I tried fixing it again. I soaked the PCB in distilled water and the IC disintegrated. I wrote about in another post.

Anyway, I managed to get a new movement complete and fixed it yesterday. But as usual it wasn't plain sailing. 

I'll continue with the details later...

[watchweasol]

Hi Hector    when is anything plain sailing,  my 10 min jobs take an hour.  thats life.    nice looking watch .

[HectorLooi]

Haha.... So true. Thanks.

[HectorLooi]

I had been searching for a replacement movement for this watch for the past 2 years. There had been other 7M22 on ebay, but the strange thing is that the layout of the components in the movement was different from the one I had. But finally I found one that was identical. And the price was very reasonable. 

When it finally arrived, I discovered that there was a capacitor installed. I assumed it was a rechargeable cell and removed it. But to my surprise, it was an original GOLD CAPACITOR! 

That means this movement must be from the late 80s or early 90s. Would a 20 year old movement still work?

I put the rechargeable cell that I bought for my old movement in and.... It works!

I lubricated it with the tiniest amount of Moebius 9000 and cased it up with no issues. Then I put the gold capacitor in and fitted the oscillating weight and gave it a whirl. But the rotor was stuck. It thought it must be dried up lubrication, so I removed the generator section and removed the winding gear and dynamo rotor. And my heart sank.... The arbor of the rotor was broken. The arbor, not the pinion!

[HectorLooi]

But everything ended well. I transplanted the generator from the old movement over to this new movement and the second hands fired up after a few whirls of the rotor.

After 5 minutes of whirling the watch, the second hand still jumps 2 second steps, indicating a low voltage condition. I was beginning to worry that the capacitor wasn't holding charge properly. I used the electric toothbrush charger trick to charge the watch for 4 hours. The watch has been running well since. I have been wearing it for the past 2 days.

[HectorLooi]

Just a couple of interesting things to add.

Elsewhere in this forum, the question of whether a toothbrush charger or smartphone wireless charger could be used to charge a Seiko Kinetic watch came up.

I noticed that this Seiko AGS can be charged this way. But I'm not sure if it works for newer Kinetic watches. One way to test is when the cell is flat, put it over the charger and move it around to find the sweet spot, when the second hand starts to move. It's something like finding the sweet spot to make the hands move on a line release tool.

And do not charge the watch for too long. I'm not sure if the charge controller switches off when a full charge is reached. 

The next interesting thing I want to bring up is carbon fibre tweezers are conductive. It might feel like plastic, be light like plastic but it conducts electricity. The resistance is in the range of 5K to 10K. 

This might not short a cell when you hold it by the flat surface, but it is discharging the cell nevertheless. 

[ifibrin]

54 minutes ago, HectorLooi said:

Just a couple of interesting things to add.

Elsewhere in this forum, the question of whether a toothbrush charger or smartphone wireless charger could be used to charge a Seiko Kinetic watch came up.

I noticed that this Seiko AGS can be charged this way. But I'm not sure if it works for newer Kinetic watches. One way to test is when the cell is flat, put it over the charger and move it around to find the sweet spot, when the second hand starts to move. It's something like finding the sweet spot to make the hands move on a line release tool.

And do not charge the watch for too long. I'm not sure if the charge controller switches off when a full charge is reached. 

The next interesting thing I want to bring up is carbon fibre tweezers are conductive. It might feel like plastic, be light like plastic but it conducts electricity. The resistance is in the range of 5K to 10K. 

This might not short a cell when you hold it by the flat surface, but it is discharging the cell nevertheless. 

Do you think a wireless charger can also function as a demagnetizer, due to the oscillating electromagnetic field? Or does the charger only start oscillating its electromagnetic field when the receiver coil of some device (like the kinetic watch) is nearby?

Just an off topic question...

[HectorLooi]

The electromagnetic field from a toothbrush charger is to weak to demagnetize anything. Those cheap, blue demagnetizer from China work reasonably well. The only problem with those is they are not designed for heavy duty usage. Pressing the button for more than a couple of minutes make them really warm. It will probably burn if used continously for a longer period.

[jdm]

11 hours ago, HectorLooi said:

 

The next interesting thing I want to bring up is carbon fibre tweezers are conductive. It might feel like plastic, be light like plastic but it conducts electricity. The resistance is in the range of 5K to 10K. 

That made me curious. On my new Bergeon 93303 tweezers I've measured an average of 85 KΩ over multiple tries, which is about 18 μA @1.55 V

Quote

This might not short a cell when you hold it by the flat surface, but it is discharging the cell nevertheless. 

Going with the simplest possible calculation for a small SR626SW battery rated  24 mAh, I get that it would take 1335 hours (24 ÷ 0.018) to discharge it with the tweezers.
This may not be completely accurate however tweezers flowing 18 μA current for 55 days is proportionate to a typical Myota 2035 module drawing 20 times less (0.9 μA) for 1095 days.

[HectorLooi]

14 hours ago, jdm said:

That made me curious. On my new Bergeon 93303 tweezers I've measured an average of 85 KΩ over multiple tries, which is about 18 μA @1.55 V

Mine only reads 12K this morning. I'm sure that if I used this tweezer to touch a live wire, I should be able to feel a least a bite.

Do you by any chance have a metal tweezer with carbon fibre tips? I wonder what kind of readings that would give.

[WatchingOracle]

On 7/2/2021 at 11:49 AM, HectorLooi said:

I just restored this watch yesterday which belonged to my father. I believe it's the precursor of the Seiko Kinetic. I think the AGS is short for Automatic Generator System.

It was a troublesome watch and my father had it repaired several times by the local Seiko repair centre several times. I believe the PCB was changed a couple of times and the generator once. When the gold capacitor was phased out and a rechargeable battery was put in, the battery eventually leaked and damaged the insides. So it was in my dad's drawer for decades.

I took it out several times to attempt fixing it. I washed the PCB in distilled water to remove all traces of battery juice then put a new Seiko capacitor in. It worked for a few days then stopped. That was a couple of years ago.  Recently I tried fixing it again. I soaked the PCB in distilled water and the IC disintegrated. I wrote about in another post.

Anyway, I managed to get a new movement complete and fixed it yesterday. But as usual it wasn't plain sailing. 

I'll continue with the details later...

I don't confess to being a Seiko expert but I will say i've certainly read a few tales about the AGS and the issues with the gold capacitor especially.

That time period was such a time for new innovations and tech experiments that it's not wonder issues like this cropped up for certain 'new' movement types in Seiko's inventory. As it is with the apparent shift away from Kinetic and Direct Drive watches from Seiko from about 2018, I wonder if overall the technology in the mechanism for this style of watch movement, was overall considered more problematic then the replacement tech that developed along the way (solar and spring drive).

 

Good work on getting the watch going. That's a classy minimalist slick Seiko there!