I have a dark section on my Climate control panel it is roughly half of the panel. How do I know if it is a LCD problem or the backlight bulbs? My car is a SC400 1992 70,000 miles.It had one dark spot when I bought it but now it has gotten larger. Thanks for any help or advice.

 

it has bit the dust. ebay has them some weeks for around $140 to $180 good luck.

P.S.- if you replace it, Emerald wants a bad one for parts pm her if you wanna get rid of it.

 

when your car is off, if your A/C display shows the dark spot, it would be more likely LCD fault.

When you turn on the headlight while engine is on, and if you see the dark spot on either Left, center, right side of the screen, it would be the backlight bulbs. (remember there're 3 bulbs)

Since you mention that it gets bigger, I think it is LCD problem. It's a common problem but $$ to replace
good luck