Tuttnauer 3850 ELVG-D, Руководство техника

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6.3 System ON, display lit, erroneous or fragmented digits
The reasons for that may be faulty Real Time Clock, displays or
microcontroller. Replace them or replace the complete PREDG board.
6.4 System ON, display lit, digits are not visible
♦
Check for 5 V between TP1and TP17
♦
If yes, calibrate POT 1 on PREDG board.
♦
If digits remain invisible, this may be due to a faulty display or a
faulty microcontroller. Replace them or replace the complete
PREDG board.
6.5 System ON, key responds without beeping
The problem may be with the buzzer or the buzzer driver. Replace the
complete PREDG board, replace the buzzer or transistor 2N2222A, Q1.
6.6 Exhaust valve is always on
The problem could be with the solenoid, the transistors, or the digital
control, or a bad connection.
♦
Check and connect or replace all connections to and from the
exhaust valve.
♦
The problem could be with Q4 or Q5 on the PREDG board. If after
pressing START and the water enters the chamber, the voltage on
TP11 is between 10V - 12V the control and the transistors are O.K.
If not, replace the PREDG board. At this point disconnect connector
JP2 from the AJUNC3 board, and check the valve’s control.
If the connection to the valve is OK, (please refer to the wiring
diagram) there must be a mechanical problem with the valve or the
solenoid may be damaged.
If the control is faulty, check and connect the flat cable between
AJUNC3 and PREDG, replace the cable if necessary. If this does
not help, there may be a problem in the LATCH DRIVE at U4 in
PREDG. In that case the electronics unit should be replaced.
6.7 Exhaust valve is always off
♦
Check and connect or replace the connector between the
EXHAUST valve and the AJUNC3.
♦
Repeat transistors and control checks as in 7.6 but this time the
voltage for the transistors should be vice versa: 0.0-1.0 DC. volt (on
TP11) for open position.
♦
Check and replace the valve or the coil.
6.8 Water valve is always on and there is a continuous flow of water into
the chamber.
♦
Check the valve’s solenoid and the control circuit as you have
checked the respective exhaust valve and circuit. The valve could
also be checked by pressing the MANUAL water inlet key. If water
flows in the chamber, or if there is no flow of water once the system
is initiated, the valve and its control are o.k., but the water level
detector electrode may be damaged, or the connection between the
electrode and the circuit may be bad.
♦
Check wire and connector connecting electrode to AJUNC3 board.