Thank you for your help.
I have left messages with 2 other companies and no one came back to me.
Much appreciated you the response
How many 550 sheet trays you add to a standard 6515DN.
One 550 works ok just added a second and not working
I have just bought my second 550 sheet and get an error 077-327
small tray - invoice ebay
550 sheet - invoice amazon
550 sheet - plain paper
Thank you for yor advice.