Tries to open all 6 byte files in a site collection and reports if the opening was successful or not.

Get-FilesThatWillNotOpen.ps1

Add-PSSnapin -Name Microsoft.SharePoint.PowerShell

function Get-FilesThatWillNotOpen
{
    [cmdletbinding()]
    param
    (
        [parameter(Mandatory=$true)][Microsoft.SharePoint.SPSite]$Site
    )
    
    begin
    {
    }
    process
    {
        $webs = $Site | Get-SPWeb -Limit All

        foreach( $web in $webs )
        {
            $libraries = $web.GetListsOfType([Microsoft.SharePoint.SPBaseType]::DocumentLibrary)

            foreach( $library in $libraries )
            {
                $query = New-Object Microsoft.SharePoint.SPQuery
                $query.ViewXml = "<View Scope='RecursiveAll'>
                                      <Query>
                                          <Where>
                                              <Eq>
                                                  <FieldRef Name='File_x0020_Size' />
                                                  <Value Type='Integer'>6</Value>
                                              </Eq>
                                          </Where>
                                      </Query>
                                      <ViewFields/>
                                      <RowLimit Paged='TRUE'>5000</RowLimit>
                                  </View>"

                do
                {
                    $batch = $Library.GetItems($query)
                    $query.ListItemCollectionPosition = $batch.ListItemCollectionPosition
        
                    foreach( $item in $batch )
                    {
                        $corrupt = $true

                        try
                        {
                            $item.File.OpenBinary() | Out-Null
                            $corrupt = $false
                        }
                        catch
                        {
                            $corrupt = $true
                        }

                        [PSCustomObject] @{
                            Site       = $item.ParentList.ParentWeb.Site.Url  
                            Web        = $item.ParentList.ParentWeb.Url
                            List       = $item.ParentList.Title
                            FileName   = $item.File.Name
                            FilePath   = $item.File.ServerRelativeUrl
                            IsShortcut = $item.File.Properties["evsp_Shortcut"]
                            Corrupt    = $corrupt
                        }
                    }
                }
                while($batch.ListItemCollectionPosition -ne $null)
            }
        }
    }
    end
    {
    }
}

$site = Get-SPSIte -Identity "https://sharepoint.2016.contoso.com/sites/teamsite"

Get-FilesThatWillNotOpen -Site $site -Verbose | Export-Csv -Path "FilesThatWillNotOpen_$(Get-Date -Format FileDate).csv" -NoTypeInformation