this is a diagram of the drip tray & drip tray contacts for the Jura S-Series S Series Impressa S7, S7 Avantgarde, S8, S9, S9 Avantgarde, S90, S95, C3000 capresso 153, X70, X90, and XS90 One Touch Models.
"EMPTY TRAY" or "EMPTY GROUNDS" (on other machines) is activated when the 2 metal contacts can complete an low volt electrical circuit through high waste water or wet caked-on coffee grounds. the area is marked in RED. careful examine this area and observe the obstruction and gunk and compare with bare clean black abs plastic. the gunk is dull and rough. use soft tools (toothpick, bamboo skewer) to scratch through the gunk. use warm water and soap and a low bristle height brush to thoroughly remove all buildup from this area. dry the metal contact and contacts area with a high percentage alcohol. visualize the insertion slots deep inside the machine (for the metal contacts marked 414) with a flashlight and verify that the female contact point pads have not been bent and are separate and distinct.
the GREEN arrow indicates a thin black plastic finger-like protrusion. this finger (when the tray is inserted) will press against the "TRAY MISSING" small white relay switch deep inside the machine. use a flashlight to visualize the small switch. verify that the switch is securely mounted and clicks when depressed (up) using a soft tool (bamboo skewer) and note the sound. verify the finger is not damaged or chipped off. listen for the sound very carefully when the tray is fully inserted into the machine. if it is not these preliminary factors, the relay switch should be replaced.