We've purchased a LK204-25 RS232, rev 1.23 board, 7-15V option but upon powering it up (12V) the display backlight does not turn on, and all the "pixels" are black (on).
Sending commands through RS232 has no effects, and the keypad (B204A-BK) connected to it won't produce any output on the RS232.
Any thing we should try before returning the unit? RMA-ing it from Brazil will be expensive...