Schaerer Ambiente 2 Service Manual

Chapter 6 Control system diagram
SMSO-2-02.06- 15.07.03 225
6.5.37 Refrigerator, ventilation valve
36V 5V DC

36V S L1, N
Operating condition
The ventilation valve (closed at zero current) opens when the milk serving has ended.
Symptoms
The ventilation valve is not functioning.
Procedure
Process
step
Check Possible cause Remedy
1
Measure voltage at plug X39 5 on
power PCB:
36 V DC ?
 Check the voltage supply (see
“Power PCB, control voltage”)
 Voltage supply failure / faulty
2
Measure voltage at plug-in con-
nection (4) between machine and
refrigerator (interface)
36 V DC ?
 Plug contacts on power PCB
faulty / oxidised
 Cable broken or pulled out of plug
 Check / replace plug contacts
 Replace cable
3
Voltage measurement on the
connector tongue (Input) to the
ventilation valve:
36 V DC ?
 Plug contacts on power PCB
faulty / oxidised
 Cable broken or pulled out of plug
 Flat plug not correctly connected
 Check / replace plug contacts
 Replace cable
 Re-connect the flat plug on the
plug-in contact stud
Resistance measurement at ventilation valve:
 Switch off voltage
 Pull out cable from plug-in contact studs
4
Resistance measurement at venti-
lation valve;
Nominal resistance:
19 Ω ?
 Plug in contact studs oxidised
 Faulty coil
 Replace ventilation valve
5
Carry out initial test:
Voltage measurement X39 6,
GND
0 V DC ?
 Power transistor does not switch  Replace the power PCB
Reconnect the flat plug to the
ventilation valve.
Function check: The valve must
open (audible click!)
 Cable (or) / power PCB faulty
 Mechanical fault on ventilation
valve (calcium deposit)
 Replace cable / power PCB
 Replace ventilation valve
NO
YES
YES
NO
YES
NO
Y
ES
NO
Y
ES
NO

Schaerer Ambiente 2 Specifications

General

Brand	Schaerer
Model	Ambiente 2
Category	Coffee Maker
Language	English