You can obtain the latest official firmware (currently version 3.74) directly from Sony’s support pages: Official Latest Firmware : Available on the PlayStation Support Firmware Archives
No. The official file name is PSVUPDAT.PUP exactly. Renaming a file with a version number will cause the Vita to reject it. Rename it back to PSVUPDAT.PUP before use. Psvupdat.pup Download
This requires already having Custom Firmware (HENkaku/Enso). You can obtain the latest official firmware (currently
A "brick" occurs when a console becomes unusable, functioning essentially as a brick. Rename it back to PSVUPDAT
The term “Psvupdat.pup Download” is one of the most searched phrases within the PS Vita modding and repair community. But what exactly is this file? In simple terms, the .pup extension stands for "PlayStation Update Package." This is the container format Sony uses to distribute system software updates for the PS Vita, PS3, and PSP.
How to Manually Update Your PS Vita with PSVUPDAT.PUP PSVUPDAT.PUP
If you are on a higher firmware already, Safe Mode will block installation of an older PSVUPDAT.PUP . You cannot downgrade without a hacked console.