If your drive is completely unresponsive or undetected by the flashing software, you must force the controller into hardware ROM Mode using the test points on the PCB. Unplug the SSD and open its plastic or metal casing.
Phison does not officially release firmware to consumers, but repair firmware packages are widely archived by the tech community. Locate a trusted firmware archive repository. phison ps3111-s11-13 firmware
: Use an Uninterruptible Power Supply (UPS) to prevent sudden dirty shutdowns that corrupt translation tables. If your drive is completely unresponsive or undetected
For the PS3111 specifically, there is a well-documented bug where the drive goes into a protection state due to "dirty shutdown counters." You can sometimes temporarily revive it: phison ps3111-s11-13 firmware