I created an Imacro that will check each and every account without the need to login.
I have searched for a YT account checker and the only one I found was by lamlam, the bad news is it It no longer works. But if you want you can use this code for Imacros and it will verify all your accounts.
First you will need Imacros, its a free fire fox plugin.
Next you will need to create an excel file with your usernames and passwords in it. In row "A" put all of your usernames, and in "B" put your passwords. Then all you have to do is save it as a csv (Comma Delimited) file. Just click on "save as type" and you will see this option. Make sure you save this csv in the Imacros directory under Datasources. It would look something like this:
C:\Documents and Settings\All Users\Documents\iMacros
After you have saved your csv with your account details you can add this code to your Imacros. You need to click the edit button on Imacros and add this:
Code:
VERSION BUILD=6240709 RECORDER=FX
SET !DATASOURCE youtubeaccounts.csv
SET !EXTRACT_TEST_POPUP NO
SET !DATASOURCE_COLUMNS 2
SET !ERRORIGNORE YES
FILEDELETE NAME=[COLOR="Red"]C:\Documents and Settings\All Users\Documents\iMacros[/COLOR]\goodaccounts.csv
TAB T=1
URL GOTO=http://www.youtube.com/user/{{!Col1}}
TAG POS=1 TYPE=TEXTAREA FORM=NAME:NoFormName ATTR=ID:comment_entry_box_text CONTENT={{!col1}}
TAG POS=1 TYPE=TEXTAREA FORM=NAME:NoFormName ATTR=ID:comment_entry_box_text EXTRACT=TXT
TAG POS=1 TYPE=TEXTAREA FORM=NAME:NoFormName ATTR=ID:comment_entry_box_text CONTENT={{!col2}}
TAG POS=1 TYPE=TEXTAREA FORM=NAME:NoFormName ATTR=ID:comment_entry_box_text EXTRACT=TXT
SAVEAS TYPE=EXTRACT FOLDER=[COLOR="Red"]C:\Documents and Settings\All Users\Documents\iMacros[/COLOR]\Datasources FILE=goodaccounts.csv
Next you need to locate and change the directory In red before you can run it. So find Imacros datasources on your pc and copy & paste the correct directory in this code.
Now you need to be logged into to any account on YT, it doesn't matter which account you use. You just need to be logged in so that you are able to comment. Don't worry you will not be commenting on any of your accounts. We just need the comment field so we can extract the working accounts.
So while logged in run the Imacros code above, just click "Play Loop", set the loop pretty high like "9999" and it will continue to check all your accounts til there is no more.
When Imacros finished checking all of your accounts open up excel and go to the Imacros/Datasource directory and open up " goodaccounts.csv " You will need to show all files to locate it.
So click open and at the bottom you will see "All Excel Files" change it to "Show All Files" and you will see goodaccounts.csv just click on it and open it up.
When you open the file you will see the accounts that are good along with a bunch of #EANF# To remove these form your list just click CTRL+F and remove them. Now you should have a list of all the account that are working and good.
This isn't the best way to make sure your youtube accounts are working, but it's better then nothing. If you need help just ask...