If the power cut out during the flash, the printer might refuse to boot. You may need to boot the machine into "Tech Mode" or "Force Download Mode" by holding specific button combinations (usually holding the Stop/Clear button while turning the machine on) to clear the corrupt memory space.
The official Samsung SCX-4300 driver must already be installed. Step 1: Download the Firmware File samsung scx-4300 firmware 1.25 download