Jura J9 drip tray not fitted

A customer recently presented me with a faulty machine, that he was given, oh here we go I thought, no bodies that generous. It had to have some expensive non reparable fault, right! –
Wrong!, this fault was so simple I thought I better post it and perhaps save someone else giving away their Jura coffee machine or paying $300 for a fix that costs nothing. I charged him $90 but I also dismantled the brew unit, serviced it, the hydraulic o-rings and got the machine making decent coffee.

Anyway the fault would only appear when the machine was hot and it would cause the error message “drip tray not fitted”, it would display then go, then display. Obviously the drip tray was fitted and no amount of removing it and putting it back would convince the machine of that fact. The customer resolved the issue by turning off the machine. The previous owner had been told it was a board issue that needs to reset with a power down.

The reality was that the issue was just a simple loose connection. If you look carefully inside the J9 and other Jura’s they have 3 connections on the body (see photo below) that connect onto the drip tray (when it is inserted) that only has 2 metal connectors. When the try is pushed in it bridges connection 2 and 3 (from left), this closes the circuit and pulls a pin down on the micro, as pin 3 is ground. This pull down switch tells the software that the tray is in place. So in order for the tray to be detected, pin 2 must be connected to pin3. When the tray get full of water this then connects pin 1 to pin 2 and 3, thus it pulls the micro pin attached to connection 1 low, telling the software the tray is full of water.

jura connections pins

The fault here was that pin 2 was loose, so when the connectors got hot, the connection became intermittent and the tray failed to be detected. The solution was simply to squeeze the spade connector tighter.
The lesson, check connections and micro switches before you suspect a board error and definitely before you give the machine away.

jura tray connectors