Unable to flash code to ESP32 CAM

[joel_kruger]

I am using an Arduino Uno to flash code to my ESP32 cam dev board via UART and have made all the necessary connections (5V, GND, UOR, UOT, put in flash mode by grounding IO0), but the board is not getting picked up at all (error: A fatal error occurred: Failed to connect to ESP32: Timed out waiting for packet header). I've included the necessary libraries and the additional ESP32 URL.

Could this mean that my dev board is broken? I've done some signal and voltage tests and it seems as though my VCC and GND pins are shorted when not connected to power, not sure what this means.
No lights on the dev board turn on at all (even when I press the reset button). The 5V pin reads 4.6V so it is getting power from the Arduino Uno.

Any urgent help would be much appreciated! Thanks