How to use a multimeter

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feo

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I have a power brick that I'd like to test whether its alive or not. I bought a relatively inexpensive multimeter from Builders but I have no clue how to use it.

I've watched a couple of YouTube vids but I'd like advice from the guys here.

Basically, the power brick is for a QNAP NAS, the specs say it outputs 12V. It's got a 4 pin connector that goes into the NAS.

How would I go about testing the health of this power brick?

Model number is EA11351A-120 if that helps.
 
Set it to the DC voltage range higher than what the PSU outputs. You can put the one lead on a pin and then move the other lead between the remaining 3 pins and record the values you get. Move the lead to the next pin and repeat.

Would be easier if you knew the pinouts of the power connector, i'm sure you will be able to find something on google.
 
Pinouts?

There's a PDF file of the specs of the power brick on the manufacturers website but I'm not really sure what any of it means.
 
Well, the black will be negative, the red maybe 5 volts and the black 12 volts. All DC, so put the selector on 20 volts DC. DC may be represented by two parallel lines while AC is represented by a sideways "S"
 
WARNING: This thread may be hazardous to your health...
 
As it shows in that pdf you can take the negative (black) lead and put it on either GND and the positive (red) lead and put it on the corresponding V+. You should get voltage on either set hopefully...

9JONdNQ.png



as louisek said put it on the DC 20 Volts. The black lead in the COM and the red lead in the voltage plugs of the multimeter.

c6ad4c6e7afa83f7_digital_multimeter.jpg


The picture is set to 200, it will just be scaling.
 
G_Unit said:
As it shows in that pdf you can take the negative (black) lead and put it on either GND and the positive (red) lead and put it on the corresponding V+. You should get voltage on either set hopefully...

9JONdNQ.png



as louisek said put it on the DC 20 Volts. The black lead in the COM and the red lead in the voltage plugs of the multimeter.

c6ad4c6e7afa83f7_digital_multimeter.jpg


The picture is set to 200, it will just be scaling.
Click to expand...

Eiish I think your picture shows the meter reading degrees Celsius
 
louisek said:
Well, the black will be negative, the red maybe 5 volts and the black 12 volts. All DC, so put the selector on 20 volts DC. DC may be represented by two parallel lines while AC is represented by a sideways "S"
Click to expand...

Are you married?
Works in a law office & can use a multimeter:love:
 
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.
 
Last edited:
Red - Centre i think but better to double check with someone else 1st
Black - Com
Switch to V~ 500V
 
If you're testing voltage then plug the black probe into the right hand socket and the red probe into the middle. Make sure to select AC for testing the kettle socket and DC for testing the output from the power supply.

Let's just let another forumite confirm before you write yourself off....
 
Tun@ said:
Red - Centre i think but better to double check with someone else 1st
Black - Com
Switch to V~ 500V
Click to expand...

But the power brick outputs DC 12V...shouldn't I set it to 20 DC on the meter?

riscbroker said:
If you're testing voltage then plug the black probe into the right hand socket and the red probe into the middle. Make sure to select AC for testing the kettle socket and DC for testing the output from the power supply.

Let's just let another forumite confirm before you write yourself off....
Click to expand...

Ok anyone else can confirm this?
 
riscbroker said:
If you're testing voltage then plug the black probe into the right hand socket and the red probe into the middle. Make sure to select AC for testing the kettle socket and DC for testing the output from the power supply.

Let's just let another forumite confirm before you write yourself off....
Click to expand...

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