Testing an AC adapter using a multi meter - what settings go where?

multi meter
Hi the black and red rods have a choice of three holes - which ones?
Also the rotational dial goes where?

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nobusConnect With a Mentor Commented:
>>  Hi the black and red rods have a choice of three holes - which ones?   <<  see above
the 3rd one is for measuring DC Amperes up t o 10 A DC
>>   Also the rotational dial goes where?   << since most ac adapters output 18 - 19.5 V the 20 V DC position seems the best; if unsure start from the 200V, then switch to lower

to show all, here a picture  :
JohnBusiness Consultant (Owner)Commented:
Most adapters put out 20 Volts or less, so choose a setting like 20 or 50 volts on the meter (rotational dial). Use the DC setting, not AC. Then test the holes in pairs to see if any pair produces 20 volts (or -20 volts, depending on how you connect. ... Thinkpads_User
☠ MASQ ☠Connect With a Mentor Commented:
Good thing about it being a digital meter is it doesn't much matter about the polarity.
Black lead goes in the COM socket and is nominally negative.  For the the voltages your talking about the red lead goes in the socket immediately above.  Set the dial to DCV in the range the adapter says it puts out.
If this is a laptop adaptor you may have a cylindrical plug with a central pin  the cylinder may have separate internal and external surfaces that you need to check the potential across while the pin will have a lower voltage.  The adaptor label should also show polarity for the DC output to give you an idea about whether the outside is positive or (more likely) negative.  If you get a negative reading for DC volts then it just means the surface you've got the red probe on should actually have the black one!
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☠ MASQ ☠Commented:
Which is pretty much what thinkpads_user has already covered.
Shouldn't go for a coffee mid-post :)
fcekAuthor Commented:
Im going to test the ideas here soon
nobusConnect With a Mentor Commented:
note that you must load the PS -  otherwise it still can be bad  when connected to mobo
fcekAuthor Commented:
Im going to test this over the weekend thanks.
fcekAuthor Commented:
Well like the person with new orthopaedic shoes, I stand corrected.

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