LAVAZZA LB 4712 Maintenance Manual page 29

Maintenance manual for technical assistance
PROBLEM
The pressure gauge indicates an
unacceptable pressure
Grounds in cup
coffee is dispensed with the ma-
nual key only.
unacceptable coffee dispensing.
The coffee dose is not met.
The led of the dose key flashes.
Manual code 10066846 / Rel. 0.00 / March 2012
CAUSE
The pressure gauge is defective.
The boiler calibration is incorrect.
The power-pump calibration is incorrect.
The capsule-holder is dirty.
The lower perforator holes are worn.
The internal gasket is worn.
The temperature of the dispensed water
is high.
The fuse of the control unit is damaged.
defective keyboard.
The connection of the flowmeter is de-
fective.
The connection of the electronic control
unit is defective.
The connector of the flowmeter has hu-
midity on it.
The flowmeter is defective: during bre-
wing the flowmeter led does not flash.
The one-way valve loses pressure (the
dose is too small).
The discharge valves lose pressure (the
dose is too small).
Water leakage from the unit solenoid
valve during coffee brewing or when at
resting position.
The flowmeter is partially clogged.
SOLUTION
Replace the pressure gauge.
adjust the calibration of the boiler.
adjust the calibration of the power-
pump.
clean the capsule-holder.
Replace the lower perforator.
Replace the gasket.
check the cause and remedy any
problems.
Replace the fuse of the control unit
(1a).
Replace the keyboard.
check for proper connection of the
flowmeter.
check for proper connection of the 8-
pin connector of the electronic control
unit.
Remove the connector of the flow-
meter and dry the contacts.
Replace the heads of the flowmeter
or the whole flowmeter.
check and replace the one-way
valve, if necessary.
check and replace the discharge val-
ves.
clean and replace the solenoid valve,
if necessary.
clean or replace the flowmeter.
25