This is a simple script that can be used to interactively check an AD account

Test-ADCredentials.ps1

$Domain = $env:USERDOMAIN
# comment out the credential line if you want to cache this
Clear-Variable -Name Credential*
$Credential = $( Get-Credential -Message "Please provide AD credentials to test.  There is no need to add the domain if it is '$Domain\'" )

if ($Credential)
{
    $Context = "Domain" # Domain this is the type, not the domain name - i.e. as opposed to Local auth, or ADLS

    # now the magic happens
    Add-Type -AssemblyName System.DirectoryServices.AccountManagement
    $DS = New-Object System.DirectoryServices.AccountManagement.PrincipalContext([System.DirectoryServices.AccountManagement.ContextType]::$Context, $Domain)
    $result = $DS.ValidateCredentials($Credential.UserName, $Credential.GetNetworkCredential().password)
    $DS.Dispose()


    if ($result) 
    { $output = "works" }
    else
    { $output = "does not work" }
    
    Write-Host "`nThe password for $($Credential.UserName) $output"
}