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Thread: How to Test a Clock Mechanisim

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    Default How to Test a Clock Mechanisim

    Hi all,
    Another task I have been given..

    It's a Seikosha clock and - from what I have been told - is the original name for Seiko.

    I was asked to see why this clock wasn't working. On taking it apart I found a mass of corrosion around the crystal and (what I think), is a Resistor and all around the IC and the wires to the coil.

    I'm sure that the corrosion was from a battery.

    I have done my best to clean it up, but when I 'really' lightly touched the crystal (C), it popped off!
    From my understanding the crystal isn't polerised.

    The metal contacts for the crystal were very badly corroded and had tons of gunk on them.

    To explain the horrible soldering: The metal that the C was connected to did not want to be soldered! So I had to wrap some very thin wire to the back of the post, solder that up tight, then connect the C's legs.

    I think there is a Resistor on POS side, but so much gunk, I haven't been able to take a reading as I'm scared of damaging the existing contacts. It's hard to solder as the contacts are sat on a plastic housing.

    The coil (Solenoid), must make the little cog that sits into that small opening of that metal plate that one can see 'north' of the IC and I guess make it spin in short pulses...?


    Any ideas on how can I see, using a multimeter, if the Coil is actually working or in fact the IC has gone or even testing the Crystal..?

    When I put the battery in, the little cog (which must have a metal base), does nothing when inside the perimeter of that metal plate.

    PS: I have checked the Ω on the contacts I have solder and there's no touching.



    Cheers,
    GT250.



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    the only thing you can do is set your dmm to acv lowest range and sit there to see if you get a pulse on the coil theres a lump of black gunk on the b/d and under it is a transister that turns on the coil volts so good luck ??? btu the other thing you can do is go to the nearest 2$ shop and buy another mech thats similar and replace it
    are you a self appointed hypocrite sheriff or just a nasty person

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    If your multimeter can do frequency, you could sus it out from there ; I'd be more concerned the battery leak/electrolyte has followed the copper tracks and crept under the epoxy covered COB. I suppose you could put a led across the coil outputs ; you should see a 1Hz flash.

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    Hinekadon,

    There was LOT's of black gunk everywhere! I think it's a very old clock.
    What is the b/d..?

    Why would I choose AC'v' to see a pulse, if the battery is DC? On my Fluke 289, should I select the LoZ setting?

    With regards to getting another mech: This mech only operates a small 3" dial at the base of the main face. And only has ONE spindle. 60 at the top and 30 at the bottom.

    The main clock works fine and (What I think), has a Year blue faced moon picture dial that appears to move with the gear ratio's really slowly, and I mean slowly...!

    The main clock only has H&M. So I thought that lower dial might be the Seconds. However, on rotating the cogs inside manually - just a 1/4 turn with a finger every two seconds - It doesn't seem to be that, but I'm not sure.

    So if I can get a replacement mech, I'm ok with that. But I don't know what the 'ratio' is.


    Wotnot,
    Yes, I don't know what damage the corrosion has done and if it has indeed 'crept' into the COB (Chip on Board?).

    I'm not sure about that R as well! I have tried to measure it, but get nothing due to the gunk. It's all so small, I'm scared to scrape harder/deeper.

    I have a Fluke 289. So will that do the freq of the crystal?
    If so: When the battery is connected you are saying that I should be able to measure if the C is oscillating - if working, on the two legs?


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    sorry mis read your op I thought it was the clock mech - the reason for using acv is that some pulses are positive going but most actions are on the neg side and are easier to pick up that way the gunk i was referring to was the "cob" your fluke wont pick up 1 pulse per second except on acv cheers don
    are you a self appointed hypocrite sheriff or just a nasty person

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    Would anyone know what 'Ratio' the lower dial is?
    Is it seconds ? Only has a single spindle.

    I tried to find a 60second clock mech but no luck. I'd have to remove the internals as the orig mech has pre molded screw mounts.

    The Hour and Minute mech wasn't working and the Moon dial wasn't. I have now repaired those, so the top part works fine. There is no second spindle.

    Would just like to know what the lower dial does.




    Cheers,
    GT250

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    I'd say seconds

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    yes its seconds don
    are you a self appointed hypocrite sheriff or just a nasty person

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    A cheapo replacement movement will work and just insert the seconds hand, you just have to shorten it so fits nicely in the circle.

    Cool is to get a sweeping movement, which you might need to order on Ebay.
    I will post a link from movements I actually ordered because a lot are rubbish and only have 3 months battery life.
    Edit:
    The ones I ordered had no hands and it was a nightmare to get a seconds hand to fit. Was also sent from China
    This one looks right. It has the large coil like the good ones I got, hands to choose and sent locally:
    Last edited by Uncle Fester; 22-03-20 at 02:59 PM.
    This era of thoughtless consumption must end so we can encourage a world of creative geniuses rather than consumer idiots.


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    Thanks for all your replies people.

    Uncle Fester, I might have a clock mech (does S/M/H), and is silent. I might be able to use it..!

    I'll have a look at the molding of it and see about the fitting and I guess the size of the hand might be an issue as well as it actually fitting.

    I'll have a go in the next few days..

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    This site is from the USA it has a good range of mechanisms and clock hands plus video tips


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    Hi all,

    I have managed to fit a normal silent mech clock (H/M/S), in place of the Second hand dial area, as recommended by Uncle Fester.

    Must admit I didn't think of that as I was mind set in trying to obtain a single spindle 60 sec mech.

    Had to do a support bracket as the new mech had no mounting options. Also had to trim the length of the original Second hand arm as it sat to proud on the new mech and the Minute arm would come into contact with it.
    Then some fine 0.5mm drilling down the middle of the newly trimmed shaft

    In the end the hex face fitted with no arm spindles touching the glass. The back of the clock also fitted (just!), as the new mech was thicker/higher at the back - mixture of front spindles into the face - or the mech brought back into the clock, in the end it all went well and is keeping great time.

    And all silent: I hate ticking clocks...!! Just amazing how a 'tick' can keep you up at night...





    And many thanks for all the people who helped me.

    Hope all is well and keep isolated as much as possible. This virus is VERY contagious and if anyone (especially over 70), gets it, then they are in trouble!
    GT250.

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    Well done GT250 nice job
    are you a self appointed hypocrite sheriff or just a nasty person

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    Good repair - well done mate

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    Looks like a bought one! Well done!
    I'm out of my mind, but feel free to leave a message...

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