Live equipment chassis

A mate of mine is reporting that he gets a small electrical shock when he touches the chassis of his audio equipment.

While i'm aware of several instances that can give rise to this happening does anyone here have (or point me towards) a simple methodical guide for him to follow to find the cause? Thanks.

Can you be more specific?..... Other than a static electricity charge shock an electrical shock from our home's electrical power source requires a point of entry and a point/s of exit.
Example, in one hand out the other. Or from a hand and out bare feet to a bare concrete floor. Just two examples....

Is your friend touching another piece of equipment or some object that is grounded with his other hand?
There has to be a difference of potential, voltage, between the two contacted objects.
Where is the current flow path?

As for the piece of equipment. Two wire or three wire cord and plug? If three wire is he using a ground cheater?

If a three wire cord and plug is the safety equipment ground on the receptacle connected all the way back to the neutral bus at the electrical panel?

Does he have a multimeter to do some tests?

Food for thought.... Birds perch on high voltage power lines and never receive an electrical shock.

When a squirrel jumps onto a high voltage power line, he runs down the wire without any problem at all. It's the dismount that gets him. In the end while still on the power line the first part of his body to touch a grounded object.... goodbye squirrel.
That does it, I'm getting a squirrel to keep in my pocket as an equipment tester.

He can jump on the stereo and If he falls dead on the floor, I'm leaving without listening.

LOL, or you could get a 25% stainless steel thread suit like this guy wears.
Think of the income potential, equipping all those squirrels out there with miniature Faraday Cage suits. I'll bet Obama and the ASPCA would finance it! Well- It would end up coming out of taxpayer pockets, but........
Are we as a nation becoming Fascist? I mean melting pot is old stuff. If you do not agree with the right wingers, they want to (basically) get rid of you. Thanks Rodman99999 for making ANOTHER cheap shot that demeans this site.
Actually- The nation is becoming more Socialist by the minute, in case you haven't noticed(are you a blond, by chance?). Funny, how little sense of humor Liberals have!! BTW- You're quite welcome.
Have him get a polarity tester at the hardware store an outlet could be wired wrong.
Thanks Jea48 & Hevac1,

The poor chap was getting electric shocks from touching the chassis of any of his audio kit (not static charge). All product used 3 wire cord and plugs.

I initially suspected that the cause would be at the outlet but a check found the earth in place and the phase and neutral correctly wired all the way back to the switchboard panel.

It then came down to talking the guy through the laborous task of finding where circuit was being broken.

It turned out that a new (expensive) power cable was at fault (live was not conductive from his MM reading).

So everyone might like to know that the Squirrel lived.

Lucky squirrel.
So everyone might like to know that the Squirrel lived.

Lucky squirrel.

Yay, no more butt dialing...
If you keep the squirrel in your front pocket, it'll go for your nuts.

Is that a squirrel in your pocket or are you just ...?

Squirrels are very cute when they jump up and down caused by an electrical jolt.
No squirrels were hurt while writing this.