Seiko AGS 7m22a-8A20 capacitor connections issue

[Norberto]

I am new to all this watch repair business ( posted intro here so wont repeat myself

)

I bought this Seiko from ebay as non working a very long time ago when I first dabbled (unsuccessfully) in trying to "fix" a watch. Initially I just replaced the capacitor (when I first got it all those years ago), but when it didnt work I got distracted and forgot about it. 

Since then I have discovered the watch repair channel, invested in some basic tools and taken it out from where it was hidden away and wanted to have another go.

Now, looking at it properly with some magnification, I can see that the capacitor doesnt actually make contact with anything (I did watch the YT video posted on WRC about a 7m22 and saw how the two contacts need to fit properly).

Is something missing for the right contact (as you look at picture)? It certainly looks like it shouldnt just float like that. Even with the cover plate on, there is no contact. I believe it is the correct capacitor (MT920) based on google searches, so have been a bit perplexed since day I purchased it  Perhaps all those years ago I botched it, and lost a piece while removing it with my cheap tools, but would like a second opinion.

Any thoughts or resources you could point me to?

thanks

[HectorLooi]

Hi Norberto, I recently repaired my late father's Seiko AGS. It is a rather tricky movement to repair.

You seem to be missing the battery cover and insulator. If you watch Mark's video below, at the beginning of the video when he's disassembling the watch, he first removes the battery cover and insulator before removing the capacitor.

You might be able to find the parts on eBay.

[Norberto]

1 minute ago, HectorLooi said:

Hi Norberto, I recently repaired my late father's Seiko AGS. It is a rather tricky movement to repair.

You seem to be missing the battery cover and insulator. If you watch Mark's video below, at the beginning of the video when he's disassembling the watch, he first removes the battery cover and insulator before removing the capacitor.

You might be able to find the parts on eBay.

the battery cover and insulator are actually in the picture with the capacitor, so I do have those. I have watched Mark's video and in his example there are two contacts the capacitor rests on. I seem to be missing one (I believe), thus the question.

I believe I read your post before posting my question.

8 minutes ago, HectorLooi said:

Hi Norberto, I recently repaired my late father's Seiko AGS. It is a rather tricky movement to repair.

You seem to be missing the battery cover and insulator. If you watch Mark's video below, at the beginning of the video when he's disassembling the watch, he first removes the battery cover and insulator before removing the capacitor.

You might be able to find the parts on eBay.

i do actually have the battery cover and insulator, you can actually see those in the shot of the capacitor in my post.

I have watched Mark's video and his example had two contacts where the capacitor made contact, where I dont thus the question.

I actually read your post before posting my question to see if there was anything already on the forum, but you may have had a different issue.

I plan to disassemble the watch when I pluck up the courage, but wanted to get a view from the folks here first, as I do feel something is missing on the watch.

I may look for another AGS on ebay too, to get either a donor or watch to compare it to.

thanks

[HectorLooi]

Did you buy the capacitor recently? If you did, chances are it's not a true capacitor but a rechargeable lithium battery.

When handling the battery, you have to be very careful not to short the terminals. The gap between the -ve strap and the +ve body is very small. It is very easy to accidentally short the battery with metal tweezers.

I'm not sure if your circuit board is the later version, designed for lithium batteries or if it's the early version designed for a capacitor. I suspect that putting a battery in the early models can actually damage the circuitry. I think I did write about it in my original post, there are 2 versions of the 7M22A movements. I had to wait 3 years before I managed to get the correct version for my father's watch.

[Norberto]

I guess I bought the replacement capacitor about 3-4 years ago (probably longer) when I first tried replacing it. 

How do you tell what version of circuit board it is?

didnt realise the risk with capacitor so will need to be more careful.

I did find this https://www.seikoserviceusa.com/uploads/datasheets/7M22A.pdf which I will need to spend time understanding, but still not clear on whether both those contacts should be making a connection or not to complete any circuit.

thanks for responding

[Norberto]

24 minutes ago, HectorLooi said:

Did you buy the capacitor recently? If you did, chances are it's not a true capacitor but a rechargeable lithium battery.

When handling the battery, you have to be very careful not to short the terminals. The gap between the -ve strap and the +ve body is very small. It is very easy to accidentally short the battery with metal tweezers.

I'm not sure if your circuit board is the later version, designed for lithium batteries or if it's the early version designed for a capacitor. I suspect that putting a battery in the early models can actually damage the circuitry. I think I did write about it in my original post, there are 2 versions of the 7M22A movements. I had to wait 3 years before I managed to get the correct version for my father's watch.

just rewatching Mark's video and I notice that his is a 7M22B (mine is a 7M22A).

I also saw that one side of his capacitor contact doesnt make contact to a metal contact, which makes sense as you only need one connection for the negative (I Guess). so my novice assumptions are off and there is some more fundamental problem (thus why it was sold in first place).

I need to double check the positive is making a proper contact and recheck the capacitor.

[HectorLooi]

I just took apart my AGS. Looks like I have the same version as yours. I think you need a true capacitor for this version. I suspect these earlier versions were not designed for rechargeable batteries and do not have a charge contoller to prevent overcharging and overdischarging.

I took a photo of the capacitor in my watch and the little terminal on the right side is just dangling in the air.

[Norberto]

17 hours ago, HectorLooi said:

I just took apart my AGS. Looks like I have the same version as yours. I think you need a true capacitor for this version. I suspect these earlier versions were not designed for rechargeable batteries and do not have a charge contoller to prevent overcharging and overdischarging.

I took a photo of the capacitor in my watch and the little terminal on the right side is just dangling in the air.

thanks for looking. I can also see the contact in your pictures on the positive +ve below (much clearer than my pictures). I will keep investigating and look again at sourcing an appropriate capacitor.

 

thanks again