Someone went to get their tefillin checked before their chasanah and discovered the parshiyos in the Tefillin Shel Yad was put in upside down. The M"B and SA HaRav both say this is pasul even b'dieved. Are there however any poskim that say this is kosher b'dieved?
(I realize their is shitas R"T that says it should be put in "lying down". However despite this the poskim still say in a case of when it was turned upside down completely that it's pasul even b'dieved.)