New Quartz Crystal Break In Period?

[abem]

Hi.

I just got a new Hamilton QED II Dress watch:
http://www.timetrafficker.com/watches/l ... index.html

It arrived DOA but I noticed that it would occasionally display a single complete digit so I thought the chip might be ok and it would be worth trying to replace the quartz crystal. I soldered in a new quartz crystal and Voila. Life! A few minutes after I replaced the crystal, it flaked out a bit for a couple of minutes and then went back to working again. It has been working properly now for about a day.

I'm wondering if perhaps there is a quartz crystal break in period? Can I expect the watch to continue to function flawlessly or do you think the occasional glitch that I saw after replacing the quartz was indicative of something else.

-abe.

[Kasper]

a nice one Abe, great work changing the quartz.

[bucko170]

I thought the breaking in period was to do with the accuracy of the timing with new crystals having a tendency to run fast or slow for the first six months or so?

[abem]

Hmm, the module worked great for a day and a half, then briefly flaked out once today and now it's back to fine again. No idea. Sometimes I think that perhaps it's adverse to the heat and humidity that we've been having? Maybe it will settle down and be good or maybe it will flake out every once in awhile. Hard to say.

When it flakes out, the digits flicker and then it will either go dark for a few minutes or one of the digits will remain lit and then I have to loosen the back and break the connection. Leave it alone for a few minutes and then all is well again. It remembers the time and date during its flakey periods so when it comes back, I usually just have to advance the time a few minutes to make up for period that it's having its little epileptic fit.

Electronics are a mystery to me - Yes, I know the basics of how it's supposed to work, but when something isn't working right, I feel like it might as well be run by little fairies.

-abe.

[Kasper]

Abe, maybe you've read my post about my Handok dot matrix that suddenly suffers from fading digits. Still havent found out what the raison was.

-First it looks like a battery drain..but the batt is ok (checked it with a new one to)
-then checked everything for bad contact...still havent found any.

so i'm also interested what can cause it..so suddenly out of the blue. Where are the electronica specialists here????

[charger105]

Quite often (I've heard and have found) replacing the quartz may fix a module with a flakey oscillator simply through the heat that's been introduced. It probably would have fired up if you'd have just hit the original quartz legs with the iron.
You think that you had a bad QC, but it soon dies again.

One theory is that the salts left behind after a battery leak are hygroscopic..........they absorb moisture from the atmosphere. Heating things drives the moisture out briefly, but it soon re-absorbs from the atmosphere.
Of course it could just be a bad connection somewhere which becomes good as things expand with a little heat.

I've found that these Frontier modules are a bit hit and miss. Old Joe posted a while back talking about the laser trimming of the surface resistors (the rectangular black things that look like paint)......I can't remember exactly how you refer to them. Anyway, he said they were sealed with some sort of glass coating, but trimming them to the perfect value exposed the edges and potential ingress of salts etc.
Or was it Old Tom ? Here he mentions it:

viewtopic.php?f=37&t=4182&p=27183&hilit=frontier+resistor#p27183

Finally found it . Here's Old Joe's info:
viewtopic.php?f=64&t=5011&p=32840&hilit=frontier+resistor#p32840



I've also seen that the springs in the carrier push the board away from the batteries if the lid isn't closing firmly. Hence a flakey battery connection. The plastic latches degrade a bit every time you take the lid off. Try running it out of the case with pegs or something keeping the lid frimly down.
I hope you get it working Abe.
Rgds.

[Ade51]

Hi Abe,

One of my QED IIs with the frontier does a similar thing if I wear it for a long time and it gets too hot. Take it off for a while and it comes back although it may lose half an hour or so.

I'll be interested if the reason for this is found.