Run MPALL_F1_7F00_DL07_v503_0A.exe as an administrator.
Phison MPALL v5.03.0A-DL07: The Definitive Guide to USB Repair Phison Mpall V5.03.0a-dl07
Check the box if you are performing a full firmware overwrite. Run MPALL_F1_7F00_DL07_v503_0A
Fix drives showing 0MB or incorrect storage sizes. Phison Mpall V5.03.0a-dl07