I had a custome who was using our USB to Parallel Adapter with an
older HP printer. It all installed fine, and he could print the test
page perfectly, but when he used any other applications, like a
spreadsheet or even a notepad document, the printer seemed to be
working, but the page came out blank. the printer ran through the page
line by line, but never printed any ink.
It turned out that he disabled spooling, from the printers and faxes
folder. He opened the printer properties and checked a box that said
“Print directly to the printer” It printed all of his documents.