If your DP-9000 display is too dark or too light for you to read it easily, adjust the display contrast as described here.
If the display is showing unusual characters or is otherwise acting strangely, you may need to reset the DP-9000's RAM. First, if possible, print out your setups (by pressing and holding the Print key while in Setup mode until the DP-9000 double-beeps) because you will need to re-enter them after the memory is reset. Then, press the Right Arrow key, the Left Arrow key, and the Read key all at the same time and hold them until the DP-9000 double-beeps. The RAM will be cleared and reset. [For D25 DP-9000s ONLY, enter the Lamp Setup (Diagnostics mode) and adjust the lamp current until the lamp voltage matches that indicated on the installed lamp. (The lamp current will usually be around 65% - 70%.)] For all instruments, re-enter the needed setups.
If the display will not turn on at all on pressing any key on the keypad, instrument service may be required.
If additional assistance is required, you may contact HunterLab.