How to check a Live Chassis

How do i check if the Chassis is Live i don't want to touch my hands on the chassic because thats like 300Volts going straight into me and thats a bad shock is there ways to check methods for a Live chassis

I seen the AC wires REVERSED and that causes the chassis to be live
but every piece of gear is different so how do you know if the chassis it live when you turn on the piece of gear without putting your hands on the chassic ?

You can use a screwdriver type tester (A screwdriver with built in LED which glows when you coonect the tip of driver to live terminal and your hand on the top pf driver)

a screwdriver type tester what is this called?

a AC screwdriver tester?

We called it simply tester (used when i was kid)
Better just go to the electronics shop and explain him what you need may be he will understand

What makes or cause a chassis to become HOT or live?

chassis' get HOT usually only during fault conditions (rarely is it done purposesly, like "float the scope" situations). faults like a wire breaking lose and touching the chassis, or AC wires in reverse can make the chassis go HOT.

to check, use a volt meter and touch the chassis, the other pin of the volt meter insert into the GROUND pin of a receptical, or touch the cold water pipe of a house. chassis should read 0V, or close to 0V. anything over 1.5V is probably bad.

Mr.Cool

Added after 2 minutes:

it is helpful if you know if the chassis is HOT because of a DC connection touching the case, or an AC wire. keep in mind that if your meter is on DC and you are measuring your AC hot chassis, your meter will read zero and you will be fooled!!

best just select DC on your meter measure & check for zero volts. then switch meter to AC and check for zero volts.

best just select DC on your meter measure & check for zero volts. then switch meter to AC and check for zero volts.

So AC voltage= 0 volts
and DC voltage= 0 volts

to be safe have to check both if anything is 2 volts its live chassis ?

a wire breaking lose and touching the chassis

a AC wire touching the chassis?
a DC wife touching the chassis?

If the cables of the AC line wire is connected normal what would make the chassis HOT or live ?