On 2/21/2024 4:59 PM, Peter wrote:
> I still use a Casio EX-Z60 compact camera from around 2005.
>
> The problem is it discharges the lithium battery within a couple of
> weeks when left (unused) on standby. It never used to do this.
>
> It is the same with a new replacement battery.
>
> Why is this? Is there something in the electronics (capacitors perhaps?)
> which degrade over time and cause a current drain?
>
I have a device here, with 4000 series CMOS in it.
One day, it started playing games.
The circuit, is an "auto-off" circuit.
Well, unfortunately, it uses capacitors to time
a ten minute interval (film caps, not electrolytics).
And something about those acted up, causing the
power switching circuit to malfunction and drain the battery.
I don't know what exactly fixed it. I had removed
the battery for a week or so, hoping leakage currents
would drain any portions of the circuit not working
properly. That didn't help. But maybe some transient
of putting the battery in and removing it, reset something.
It's been several years since that happened, and the
auto-off has been fine the whole time.
*******
Note that, cameras in the past, contained an RTC (real time clock).
Sometimes this is based on a second smaller battery. I've had one
old digital camera (Kodak), the *instant* I attempted to use the
menu item to adjust the time setting, the screen went black
and the camera never started ever again. As they say,
shit happens. Some sort of planned obsolescence I would
guess. I would not mind working on it, but at the time,
I googled my ass off, and absolutely nobody has taken
one apart, or noted any foibles. I have no hints where to start.
And with some cameras, there are all sorts of things that
you cannot be careless with. They're designed as a trap
for the unwary. That's why I won't venture in, without
at least a little documentation.
Paul