Can You Build a PlayStation Vita from Scratch?

No. The Vita is a highly integrated consumer-electronics device requiring:

• Custom SoC (ARM Cortex-A9 quad-core + PowerVR SGX543MP4+ GPU).
• 5″ OLED (1000) or LCD (2000) multi-touch panel with proprietary controller.
• Proprietary NVG flash memory cards (not standard microSD).
• Secure boot chain, signed firmware, encrypted file system.
• Cleanroom assembly (BGA soldering, flex-cable routing).

What You *Can* Do

• Repair: Replace screen, battery, analog sticks, game card slot (guides on iFixit). Parts available on eBay/AliExpress.
• Mod (HENkaku / h-encore): Install custom firmware → homebrew, plugins, PS1/PSP emulators, SD2Vita adapter (microSD).
• Learn electronics: Start with Arduino/Raspberry Pi Pico, then FPGA dev boards to understand SoC design.

Better Alternatives

• Buy a used Vita (≈$100–$180) – huge library + homebrew potential.
• PlayStation 4/5 Remote Play on phone/tablet/PC.
• Steam Deck / ROG Ally for portable PC gaming.

Building a Vita is beyond hobbyist scope; modding an existing unit is the realistic path.