How to use a multimeter

[riscbroker]

Where do I stick the red and black probes for testing the "kettle socket" power cord?

The two outer holes. Center hole will be earth, stay away from that.

 

[biometrics]

Oh boy ...

 

[feo]

The two outer holes. Center hole will be earth, stay away from that.

Ok now you've scared me.

I'm rather playing around with my printers power brick which works fine just to see if I can get a reading.

It outputs 32V DC but I can't figure out which pin is positive and negative. It's got 3 prongs next to each other. The part number is 0957-2269.

http://www.amazon.com/HP-Adapter-Select-Printers-0957-2269/dp/B003X0GCGU

Which one of the holes on the purple plug is + and which is -?

 

[riscbroker]

http://learn.adafruit.com/multimeters/voltage

Have a look at this site, it will give you a background idea of how things work. Just bear in mind that mains voltage can be lethal.

I had a look at images of your printers power supply - I guess the centre pin will be negative and the 2 outer pins will be positive. Set your meter to DC voltage and try it.

 

[Tun@]

But the power brick outputs DC 12V...shouldn't I set it to 20 DC on the meter?
Ok anyone else can confirm this?

My post was in reply to your wanting to test the AC side - as per below

I want to first test the power cord that goes into the power brick before testing the 4 pin output one.

It's a stock standard power cable. Like the one that you plug into a computer PSU. How would I test that?

Move the switch to the V ~ (higher than 200) position & do similar as described before.
Note the "~" very important....."~" = AC............the straight line = DC.
Its the top 2 ones you need to measure i think if its a kettle plug your talking about.

You got AC INTO the power brick & DC OUT - for testing the AC use the V~500V setting
For the DC use the V (20)straight line with the dots under it position.

If you just test the DC side & it has 12V then you don't need to test the AC side

 

[Mier]

If the pins you're testing are close together be very careful not to create a short circuit.

Why not take it to a tv repair shop to either test it or show you how to use a multimeter?

 

[feo]

Quick summary:

Used a working power cord into the brick and tested the DC side. Got a big fat ZERO reading on it.

To make sure I could actually get a reading from a working power brick, I tested the DC side of my HPs power brick and got a steady 32V as expected.

So I guess the conclusion is that the NAS power brick is dead.

 

[hislordship]

Eeeek! Please be VERY careful if playng around with mains electricity especially if you're not sure what you're doing.
Why does AC have such a kick?
Well, the 230v to 240v rating they give is the root mean square voltage, so the actual peak of that is 322v to 336v! (yes that's on a single phase power supply!)

 

[Flox]

I want to first test the power cord that goes into the power brick before testing the 4 pin output one.

It's a stock standard power cable. Like the one that you plug into a computer PSU. How would I test that?

First set the Multimeter to AC 240 or whatever the highest is, then push the 2 probes (red & black) from the multimeter into the bottom 2 holes of the power cable.. Just make sure to hold the insulated part of the probe so you don't get shocked.

*do that at your own risk