I haven't used my scope in years, and now need want to check the
vertical waveforms from the video processor to the vertical out. Where
should I have the "source" set to on the scope, and do I need to use
the probe ground when checking? Thanks again group.

"Golf" wrote in message
oups.com...
I haven't used my scope in years, and now need want to check the
vertical waveforms from the video processor to the vertical out. Where
should I have the "source" set to on the scope,

usually 'int'

and do I need to use
the probe ground when checking? Thanks again group.


it a good idea, usually. sometimes a ground is established through the AC
plugs ground but without seeing the scope or the equipment under test no one
can know if that's what you have.

"TimPerry" writes:

"Golf" wrote in message
oups.com...
I haven't used my scope in years, and now need want to check the
vertical waveforms from the video processor to the vertical out. Where
should I have the "source" set to on the scope,

usually 'int'

and do I need to use
the probe ground when checking? Thanks again group.

it a good idea, usually. sometimes a ground is established through the AC
plugs ground but without seeing the scope or the equipment under test no one
can know if that's what you have.

This raises many more questions, some of which may be SAFETY related.

What is the device being tested? A TV? If so (as well as other equipment),
it may have a HOT chassis, which is extremely dangerous to work on without
an isolation transformer. In addition to being electrocuted, there may be
fireworks when attaching the scope ground to signal ground.

More details please.

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Yes Sam, it's a Sony TV. I do have, and use an isolation transformer.
When I checked a few pins on the video processor, I kept getting the
same waveform. When I connected the probe ground, the signal trace
would dissapear. I have since fugured out what I was doing wrong. I
didn't have the trigger set to auto. This also explains why I didn't
see a trace before connecting the probe (didn't post this). I
appreciate the concern and reply. Thanks again to all who replied.

Sam Goldwasser wrote:
What is the device being tested? A TV? If so (as well as other equipment),
it may have a HOT chassis, which is extremely dangerous to work on without
an isolation transformer. In addition to being electrocuted, there may be
fireworks when attaching the scope ground to signal ground.

That's how I blew up the very first TV I worked on. It was a learning
experience. It cost me a $250 20" Stereo Sharp TV (long while ago) and
was an amazing display of colors and smells along with sparks, flames,
smoke, etc.
Those days were fun.

On Sat, 07 Jan 2006 01:56:46 GMT, Jumpster Jiver wrote:

Sam Goldwasser wrote:
What is the device being tested? A TV? If so (as well as other equipment),
it may have a HOT chassis, which is extremely dangerous to work on without
an isolation transformer. In addition to being electrocuted, there may be
fireworks when attaching the scope ground to signal ground.

That's how I blew up the very first TV I worked on. It was a learning
experience. It cost me a $250 20" Stereo Sharp TV (long while ago) and
was an amazing display of colors and smells along with sparks, flames,
smoke, etc.
Those days were fun.

The real pity of that type of experience is that - because we don't anticipate
it - we don't have videocam running to allow lasting enjoyment (and sharing) of
the spectacle.