Strange problem with microwave clock in cold weather

[Mark]

I have a J.C. Penney microwave that has served me very well for 19
years. There is one strange problem that it has that has puzzled me
for years.

When the weather gets cold, and I allow the house to get to 60-65
degrees (for long periods) during the day when I'm away, or if I'm
away for the weekend, the clock speeds up, so the time of day is
several minutes ahead of all the other clocks.

This never happens in the summer, or when I maintain the house
temperature at a steady 70 to 75.

Does anyone know what could cause this? Can cooler temperatures impact
the clock circuit?

This isn't a major problem, but it's had me scratching my head for
years.

Thanks.

Mark

 

[Jerry G.]

A component or a few from age have become thermo sensitive. This can be
easily serviced by an experienced tech who is familiar with the type of
circuits and electronics used in the clock circuit of your microwave. The
only problem he may have is if the part is not available. If the failed
part(s) is generic, then there should be no problem to fix this for you.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
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I have a J.C. Penney microwave that has served me very well for 19
years. There is one strange problem that it has that has puzzled me
for years.

When the weather gets cold, and I allow the house to get to 60-65
degrees (for long periods) during the day when I'm away, or if I'm
away for the weekend, the clock speeds up, so the time of day is
several minutes ahead of all the other clocks.

This never happens in the summer, or when I maintain the house
temperature at a steady 70 to 75.

Does anyone know what could cause this? Can cooler temperatures impact
the clock circuit?

This isn't a major problem, but it's had me scratching my head for
years.

Thanks.

Mark

 

[Arthur Jernberg]

First thought is the crystal resonator may be slightly temperature
sensitive, changing it's F(0) when cooler.

 

[jakdedert]

My watch runs slower when I don't wear it for a month or so.

jak

 

[Jim Adney]

First thought is the crystal resonator may be slightly temperature
sensitive, changing it's F(0) when cooler.

But isn't this clock most likely to be line frequency driven? In that
case I think it's a lot harder to explain.

-

 

[Sam Goldwasser]

But isn't this clock most likely to be line frequency driven? In that
case I think it's a lot harder to explain.

Wasn't this cold temperature relsted? Could be a marginal part in the
zero crossing circuitry or something else on the same power circuit
creating noise on the AC line.

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