Haier HT1006TXVE, Service Manual

Page: 16 / 23

Troubleshooting
１６
S/N
Possible
Malfunctions Possible
causes
Checking Steps Instrument Solutions
1. Eyeball whether the cable
connectors are in position on
the computer display board.
Eyeballing
1. Insert and connect in
position. If not, please go on
with step 2.
2. Eyeball whether the electric
current breaks between cable
connectors and program
selecting board.
Eyeballing
Multimeter
2. If electric current is
broken, change the program
selecting board. If not, please
go on with step 3.
1
Time
remains the
same after
revolving the
knob; or
remains the
same on part
programs
position.
Transportati
on part of
the 5 cable
connectors
(ST4-1~ST-5)
on the
program
selecting
board is all
or partly
broken.
3. Eyeball whether the line
connecting the program
selecting board and cable
connectors connecting points
breaks.
Eyeballing
Multimeter
3. If electric current is
broken, change the program
selecting board.
1. Check the S10 and ST1
terminals on the program
selecting board, X4 and X7
terminals on the power drive
board, and ST3 terminal on
the computer display board.
Eyeballing
1. Insert and connect in
position. If not, please go on
with step 2.
2. Check whether the back
connecting points on the
program selecting board are
broken; measure and test
whether the voltage between
the two ends of ST1 is 220 V.
Eyeballing
Multimeter
2. If electric current is
broken, change the program
selecting board. If the voltage
is 220V, please go on with
step 3.
3. Check the whether the back
connecting points on the
power drive board X4 are
broken; measure and test
whether the voltage between
X4-1 and X4-2 (or between J3
and J1 on the power board) is
220 V.
Eyeballing
Multimeter
3. If electric current is
broken, change the power
drive board; if the welding
point is not broken and the
voltage between J3 and J1 is
not 220V, consider checking
whether the wiring harness
is broken; if the voltage is
220V, please go on with step
4.
4. Measure and test the
silicon control diode(1S2) pin
voltage relative to the earth on
the power drive board
：
the left
is 22V DC; the right is 5V DC.
Eyeballing
Multimeter
4. If the voltage doesn’t
comply with the requirement,
change power drive board; if
it complies with the
requirement, please go on
with step 5.
5. Measure and test X7-4 and
X7-5 terminal relative to the
X7-6 voltage
：
X7-4 is 22V DC;
X 7-5 is 5V DC.
Eyeballing
Multimeter
5. If the voltage doesn’t
comply with the requirement,
change power drive board; if
it complies with the
requirement, please go on
with step 6.
2
No sound
when
buttons
pressed; no
signal on the
display
screen.
Power
supply cable
is broken.
or
Damage of
the electric
components,
such as:
chips, silicon
control,
diode, etc.
6. Measure and test ST3-3
and ST3-2 terminal relative to
the ST3-1 voltage
：
ST3-3 is
22V DC; ST3-2 is 5V DC.
Eyeballing
Multimeter
6. If the voltage doesn’t
comply with the requirement,
change the 6 connecting
lines between X7 and ST3; if
it complies with the
requirement, please change
computer display board.