[Elecraft] Kpa500 lcd display issue

[Andy Durbin]

Given that the "test pattern" may be caused by an extreme LCD contrast setting I'd suggest checking the contrast voltage that is derived from PWM signal VCONTRAST.    Contrast voltage is available of "TP2" which is connected to LCD pin 55 (VLCD).

The schematic shows VLCD range is 3 - 6.5 V.   I see a good display with LCD ADJ set anywhere between 0 and 30 so I would guess VLCD between 3 V and 4 V would give a readable display.

73,
Andy k3wyc