help with the script. not working for remote computers

Hi,
I am getting the error "RPC server is unavailable" when running this script below. I have network connectivity and can ping the computers. Please let me know if smth is wrong with the script that it is unable to update service creds on the remote computers.

THank you so much!!


[CmdletBinding()]

$UserName = "testtarget\svc"
$Password = "password"
$Service = "servicename"
$ServerN = "w03,w02,w01"

  [Parameter(Mandatory=$True,Position=5)][int]$SecondsToWait

function PowerShell-PrintErrorCodes ($strReturnCode)
{
#This function will print the right value. The error code list was extracted using the MSDN documentation for the change method as December 2014
Switch ($strReturnCode)
    {
    0{ write-host  "    0 The request was accepted." -foregroundcolor "white" -BackgroundColor "Red" }
    1{ write-host  "    1 The request is not supported." -foregroundcolor "white" -BackgroundColor "Red" }
    2{ write-host  "    2 The user did not have the necessary access."-foregroundcolor "white" -BackgroundColor "Red"}
    3{ write-host  "    3 The service cannot be stopped because other services that are running are dependent on it." -foregroundcolor "white" -BackgroundColor "Red"}
    4{ write-host  "    4 he requested control code is not valid, or it is unacceptable to the service." -foregroundcolor "white" -BackgroundColor "Red"}
    5{ write-host  "    5 The requested control code cannot be sent to the service because the state of the service (Win32_BaseService State property) is equal to 0, 1, or 2." -foregroundcolor "white" -BackgroundColor "Red"}
    6{ write-host  "    6 The service has not been started." -foregroundcolor "white" -BackgroundColor "Red"}
    7{ write-host  "    7 The service did not respond to the start request in a timely fashion." -foregroundcolor "white" -BackgroundColor "Red"}
    8{ write-host  "    8 Unknown failure when starting the service."-foregroundcolor "white" -BackgroundColor "Red" }
    9{ write-host  "    9 The directory path to the service executable file was not found." -foregroundcolor "white" -BackgroundColor "Red"}
    10{ write-host  "    10 The service is already running."-foregroundcolor "white" -BackgroundColor "Red" }
    11{ write-host  "    11 The database to add a new service is locked."-foregroundcolor "white" -BackgroundColor "Red" }
    12{ write-host  "    12 A dependency this service relies on has been removed from the system."-foregroundcolor "white" -BackgroundColor "Red" }
    13{ write-host  "    13 The service failed to find the service needed from a dependent service."-foregroundcolor "white" -BackgroundColor "Red" }
    14{ write-host  "    14 The service has been disabled from the system."-foregroundcolor "white" -BackgroundColor "Red" }
    15{ write-host  "    15 The service does not have the correct authentication to run on the system."-foregroundcolor "white" -BackgroundColor "Red" }
    16{ write-host  "    16 This service is being removed from the system."-foregroundcolor "white" -BackgroundColor "Red" }
    17{ write-host  "    17 The service has no execution thread." -foregroundcolor "white" -BackgroundColor "Red"}
    18{ write-host  "    18 The service has circular dependencies when it starts."-foregroundcolor "white" -BackgroundColor "Red" }
    19{ write-host  "    19 A service is running under the same name."-foregroundcolor "white" -BackgroundColor "Red" }
    20{ write-host  "    20 The service name has invalid characters."-foregroundcolor "white" -BackgroundColor "Red" }
    21{ write-host  "    21 Invalid parameters have been passed to the service."-foregroundcolor "white" -BackgroundColor "Red" }
    22{ write-host  "    22 The account under which this service runs is either invalid or lacks the permissions to run the service."-foregroundcolor "white" -BackgroundColor "Red" }
    23{ write-host  "    23 The service exists in the database of services available from the system."-foregroundcolor "white" -BackgroundColor "Red" }
    24{ write-host  "    24 The service is currently paused in the system."-foregroundcolor "white" -BackgroundColor "Red" }
    }
}



function PowerShell-Wait($seconds)
{
#This function will cause the script to wait n seconds
   [System.Threading.Thread]::Sleep($seconds*1000)
}


function main()
{

#The main code. This function is called at the end of the script, in line 138
$svcD=gwmi win32_service -computername $ServerN -filter "name like '%$Service%'"
write-host "----------------------------------------------------------------"  
write-host "REMEMBER TO RUN THE SCRIPT AS ADMINISTRATOR"  -foregroundcolor "RED" -backgroundcolor "yellow"


write-host "Services found:"  $svcD.Count -foregroundcolor "green"
$svcD | ForEach-Object {

write-host "Service to change user and pasword: "   $_.name -foregroundcolor "green"

write-host "----------------------------------------------------------------"  


       if ($_.state -eq 'Running')
       {
         
           write-host "    Attempting to Stop de service..."
           $Value = $_.StopService()
            if ($Value.ReturnValue -eq '0')

               {
                $Change = 1      
                $Starts = 1      
                write-host "    Service stopped" -foregroundcolor "white" -BackgroundColor "darkgreen"
                }
               Else
               {
                    write-host "    The stop action returned the following error: " -foregroundcolor "white" -BackgroundColor "Red"
                    PowerShell-PrintErrorCodes ($Value.ReturnValue)
                     $Change = 0
                     $Starts = 0
                }
       }
       Else
       {
         write-host "    As the service is not running before, is not going to be started after the change." -foregroundcolor "RED" -backgroundcolor "yellow"
         $Starts = 0
         $Change = 1
       
       }
       
           if ($Change -eq 1 )
           {
             write-host "    Attemtping to change the service..."
               #this is the method that will do the user and pasword change
               $Value = $_.change($null,$null,$null,$null,$null,$null,$UserName,$Password,$null,$null,$null)
               if ($Value.ReturnValue -eq '0')
                {
                   write-host "    Pasword and user changed" -foregroundcolor "white" -BackgroundColor "darkgreen"
                   if ($Starts -eq 1)
                        {
                            write-host "    Attemtping to start the service, waiting $SecondsToWait seconds..."
                            PowerShell-Wait ($SecondsToWait)
                            $Value =  $_.StartService()
                            if ($Value.ReturnValue -eq '0')
                                {
                                    write-host "    Service started sucsesfully" -foregroundcolor "white" -BackgroundColor "darkgreen"
                                }
                             Else
                                {
                                write-host "    Error while starting the service: " -foregroundcolor "white" -BackgroundColor "red"
                                 PowerShell-PrintErrorCodes ($Value.ReturnValue)
                                }
                        }                                                          
                    }
                Else
                 {
                 write-host "    The change action returned the following error: "  -foregroundcolor "white" -BackgroundColor "red"
                  PowerShell-PrintErrorCodes ($Value.ReturnValue)
                 }
                }                      

   write-host "----------------------------------------------------------------"    
}

write-host "PROCESS COMPLETED"  -foregroundcolor "RED" -backgroundcolor "yellow"

}

clear  #clearing  the screen

main   #Calling the main function that will do the job.