Lenovo dc jack (3000 c200) question

[hienton2]

Hello all.
I have question about IBM Lenove laptop DC jack. I do not know how it works.
It has 3 terminals. The center pin suppose +20 volt. But I do not see 20v here.
I only see +20v at the inner side of the plug ,outside of plug is ground. I have question : does the center pin
of plug will have +20v when I plug in the jack of laptop?
If center pin does not have +20v when pugged in that mean the jack is bad?
Please help.
Tom

[RealBlackStuff]

You may want to use a multi-voltmeter and measure the output of the connector of your AC-adapter. That should give you the 20V.
If not, your adapter needs to be replaced.
Put the + or Red pin of the multimeter in the opening of the plug and hold the - or Black pin against the outside ground.

[hienton2]

http://i98.photobucket.com/albums/l243/hienton2/1.jpg

I have the picture of the plug of adapter.
Why the pin at the center has nothing? This makes me very much
confused. The socket jack inside the laptop has 3 terminals ,Why? ...This jack is used for plug of adapter to plug in.Thanks for response.
Tom

Note from Moderator: Don't post images without a warning in the subject line.

[hienton2]

Sorry for that moderator.
I am new in the forum.I do not know what warning to put in. Please tell me.
Tom

[ryengineer]

snip....Please tell me.....snip

If you start a thread then you can easily do it by editing your 1st post and adding a picture warning like "image, picture, snap" etc. However when you don't start a thread then try to post images as a link and always remember a picture size shouldn't be greater than 50KB as per forum rules.

[hienton2]

I got it. Thanks moderator.
Tom