I used to service this line of analysers, but this was more than 15
years ago. I no longer have any documentation or notes. I do sort of
remember that some of the caps in that unit would go shorted at times.
Check for both high ESR caps, and shorted caps. Unfortunately you will
have to remove the caps to test for shorted ones. The ESR meter will
measure a cap that is resistive, as if it was good. Shorted or
resistive caps are usually rare, but the types of caps used in this era
of meter can do this. Start with the caps in the circuits associated
to the auto reading first.
In some models of these meters, there is an optical block that uses a
number of lamps and photo sensors. they are using optical coupling for
auto biasing some circuits to achieve isolated DC balance. I have had
some of these lamps and photo detectors go bad. HP no longer will
supply parts or support for this meter, so whatever goes bad, you will
have to substitute parts if possible. Atleast most of the components in
this era of instrument are mainly generic, and can be purchased at most
any electronics parts supplier. There are however some very critical
germanium devices used in this meter. These will be very difficult to
sub, even though they used to be very much available.
--
Greetings,
Jerry Greenberg GLG Technologies GLG
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Hi
I have a problem with my hp333 distortion analyser. It work good on
manual
seting but not on automatic. So I have to ajust it all the time I
measure
a distortion.
What can be broken inside ?
Any hint or solution ?
Thank
Bye
Gaetan
