Hello.I am facing a problem with my osciloscope.When i plug the power conector with the instrument still off im having a voltage on th ground probe...Is this natural?

 

Check the ground connection through the mains cable and the ground in the mains outlet it is plugged into.
It could also be that the ground pin in the mains socket on the 'scope is no longer connected to the chassis.

Br careful. This is a potentially lethal situation.

 

I recently added some posts regarding safe working on smp's using an isolation transformer. One thing I always did was have a small wattage mains voltage (5-15W) incandescent light bulb which was wired from the EARTH pin of the wall outlet of a different socket, and the other end connected to the chassis of the 'scope before I connected the probe earth to anything. That was so that if ever the earth on the 'scope failed and chassis became live, the bulb would light and so warn me of the danger before I either got a shock, or damaged the probe or 'scope.

 

Hello.I am facing a problem with my osciloscope.When i plug the power conector with the instrument still off im having a voltage on th ground probe...Is this natural?

What part of the world do you live?

 

Check the ground connection through the mains cable and the ground in the mains outlet it is plugged into.
It could also be that the ground pin in the mains socket on the 'scope is no longer connected to the chassis.

Br careful. This is a potentially lethal situation.

If its second hand - its entirely possible someone has lifted the earth wire in the mains plug.

The correct method is earth the scope and use an isolating transformer for the device under test.

AFAIK: Live chassis TVs & radios are a thing of the past - double insulated mains items shouldn't cause any problems, but earth loops can cause mischief on earthed items.

 

What part of the world do you live?

IP says Greece.

 

IP says Greece.

House wiring probably not an issue then??