Powershell script to check if service is started, if not then start it

A potentially simpler solution:

get-service "servicename*" | Where {$_.Status -neq 'Running'} | start-service

I think you may have over-complicated your code: If you are just checking to see if a service is running and, if not, run it and then stop re-evaluating, the following should suffice:

Good point on the refresh.

$ServiceName = 'Serenade'
$arrService = Get-Service -Name $ServiceName

while ($arrService.Status -ne 'Running')
{

    Start-Service $ServiceName
    write-host $arrService.status
    write-host 'Service starting'
    Start-Sleep -seconds 60
    $arrService.Refresh()
    if ($arrService.Status -eq 'Running')
    {
        Write-Host 'Service is now Running'
    }

}