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HP Forum Archive 21

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HP-01 Restoration
Message #1 Posted by aj04062 on 29 Sept 2012, 7:54 p.m.

Seeking assistance to find a compatible source of the trimming capacitor for HP-01 Watch.

Just got one that has had the battery tray turned too much and thus damaged some of the components on the board. Casualties are:
Crystal
trimming cap
battery tab

I can source the crystal on digikey, but have not found a source of a trimming cap like this one.

BTW, this in not my board, but a good one!

Edited: 29 Sept 2012, 7:55 p.m.

      
Re: HP-01 Restoration
Message #2 Posted by Bruce Larrabee on 30 Sept 2012, 10:05 p.m.,
in response to message #1 by aj04062

Would you like a copy of the service manual?

My guess is that you will have to hack something in to replace that trimming cap. It doesn't look like a standard part to me.

            
Re: HP-01 Restoration
Message #3 Posted by Geoff quickfall on 1 Oct 2012, 12:39 a.m.,
in response to message #2 by Bruce Larrabee

I must say, at the moment I have not tried to source a part, other than to sub a very similar early seiko trimming cap (without success).

I have one unit which was working intermittently. I traced the fault to a cracked trimming cap. That was when I tried the seiko sub.

Adam, just got home and will email you tomorrow.

      
Re: HP-01 Restoration
Message #4 Posted by Frank Boehm (Germany) on 1 Oct 2012, 9:15 a.m.,
in response to message #1 by aj04062

Just a poor man's idea: how about recreating the trimming cap as a PCB - you'll need about the same thickness and same dimensions (it's a trimmer, so values might vary a bit). It should be possible to order such parts online.
Next idea: take a look at LED watches of about the same timeframe, all of them should have such a trimmer.

      
Re: HP-01 Restoration
Message #5 Posted by BobVA on 1 Oct 2012, 8:52 p.m.,
in response to message #1 by aj04062

If the repair manual has the value of the cap, you might try to see if you can find an appropriately sized surface mount fixed cap with a value near the middle of the trimmer's range. Or two you can parallel/series to get a reasonable value.

Not great, but it might get you working until you can find something better, or at least let you proceed with trouble-shooting.

Bob


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