Connecting a serial console to QNAP TS-11x devices

If you want to connect a serial console to a QNAP TS-11x device, you'll need a 3.3V TTL to RS-232 level shifter. The serial connector is of type JST PHR-4 and the wires need to be crimped into a JST SPH-002T-P0.5S connector pin before it can be fitted inside the JST PHR-4 connector. The pin layout is as follows from left to right:

GND (white)
RX (black)
VCC (green)
TX (red)

TS-219 and serial console

Once you have connected your serial console, you can use a terminal emulation program to connect to U-Boot, the boot loader used by this device. You have to connect with 115200 baud and set the parameters to 8N1 (8 data bits, no parity, 1 stop bit). U-Boot on a separate page about U-Boot.