I am attempting to do a validation for field requirements prior to lead conversion, however, this does not seem to work as it still allows the lead to convert. Any ideas?

AND(
IsConverted = TRUE,
     RecordType.DeveloperName = "Identity",
     $User.Bypass_Validation__c = FALSE,
     ISPICKVAL(Status , "Qualified" ),
     ISPICKVAL( Estimated_usage_volumes__c,""),
ISPICKVAL( Disco__c, "Completed"),
ISBlank( Disco_Summary__c ) 

)

I currently have this as my validation, but it is allowing the lead to convert still with the disco meeting date blank, the disco blank. Qualified is our converting status.

What I need to have happen is to not allow the lead to convert unless the disco meeting is completed.

AND(
ISBLANK(Disco_Meeting_Date__c),
ISBLANK( Disco_Summary__c),
ISPICKVAL(Disco__c, "Completed"), 
ISPICKVAL( Status , "Qualified" )
)

How do I create a validation rule where a lead cannot move from SAL to Converted with out Disco Meeting Status (Date), Estimated Usage Volume(Pick List) being filled in?  But it should be able to move to other stages.