Panasonic Z5 chassis tuner/if failure when warm (TC21S1R)
 

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This is a UK spec Panasonic TC21S1R (Z5 chassis).
It works for several hour before the picture shows
some disturbance, then breaks up into snow. After
this, no channels can be located using the search
tuning, implying that the frequency has not just
drifted off but there are no signals at all. AV
input remains working.

The reason I'm having particular trouble with this
fault is that it will never show up when the set
back has been removed, even if heated with warm
air. At the moment I don't even know if the problem
is with the tuner or the IF strip.

Any help most appreciated. Please copy me on

Regards,


Colin

www.colin99.co.uk

Have you taken a good magnify glass and check the circuitry for poor quality
solder connections, esp on some of the smd devices? Does mechanically
flexing of the chassis contribute to the failure?
Colin McCormick" wrote in message
...
x-no-archive:yes

This is a UK spec Panasonic TC21S1R (Z5 chassis).
It works for several hour before the picture shows
some disturbance, then breaks up into snow. After
this, no channels can be located using the search
tuning, implying that the frequency has not just
drifted off but there are no signals at all. AV
input remains working.

The reason I'm having particular trouble with this
fault is that it will never show up when the set
back has been removed, even if heated with warm
air. At the moment I don't even know if the problem
is with the tuner or the IF strip.

Any help most appreciated. Please copy me on

Regards,


Colin

www.colin99.co.uk

Art

I did do some soldering inspection and found the
odd dry joing around the LOPT, but everything
around the tuner / IF looks good. Flexing seems
to have no bearing on it, only temperature (and
even then I can't instigate it with hot air).

I suspect a capacitor!

Colin


Art wrote:
Have you taken a good magnify glass and check the circuitry for poor quality
solder connections, esp on some of the smd devices? Does mechanically
flexing of the chassis contribute to the failure?
Colin McCormick" wrote in message
...

x-no-archive:yes

This is a UK spec Panasonic TC21S1R (Z5 chassis).
It works for several hour before the picture shows
some disturbance, then breaks up into snow. After
this, no channels can be located using the search
tuning, implying that the frequency has not just
drifted off but there are no signals at all. AV
input remains working.

The reason I'm having particular trouble with this
fault is that it will never show up when the set
back has been removed, even if heated with warm
air. At the moment I don't even know if the problem
is with the tuner or the IF strip.

Any help most appreciated. Please copy me on

Regards,


Colin

www.colin99.co.uk