LG GR-S392QVC Service Manual ▷ View online
6. TROUBLESHOOTING
- 10 -
6-1 COMPRESSOR AND ELECTRIC COMPONENTS
1
2
3
4
5
2
5
5
3
5
4
5
5
1
4
3
YES
YES
YES
YES
NO
NO
YES
YES
YES
NO
NO
NO
Power Source.
Remove the PTC-Starter
from the Compressor
and measure the voltage
between Terminal C of
Compressor and
Terminals 5 or 6 of PTC.
from the Compressor
and measure the voltage
between Terminal C of
Compressor and
Terminals 5 or 6 of PTC.
No Voltage.
(Rating Voltage
±10%)?
±10%)?
Replace OLP.
Reconnect.
Replace
PTC-Starter.
PTC-Starter.
Replace OLP.
O.K.
Check connection
condition.
condition.
OLP disconnected?
Advise the customer
to use a regular
Trans.
to use a regular
Trans.
Replace Compressor.
OLP works within
30 sec. in forcible
OLP operation by
turning instant power
on and off.
30 sec. in forcible
OLP operation by
turning instant power
on and off.
Components start in
the voltage of Rating
Voltage ±10%
below.
the voltage of Rating
Voltage ±10%
below.
Applied voltage isn't
in the range of Rating
Voltage ±10%.
in the range of Rating
Voltage ±10%.
Check the resistance
among M-C, S-C and
M-S in Motor
Compressor.
among M-C, S-C and
M-S in Motor
Compressor.
Check the resistance
of two terminals in
PTC-Starter.
of two terminals in
PTC-Starter.
Check if applying
a regular OLP.
a regular OLP.
Measure minimum
starting voltage after 5
min. for balancing cycle
pressure and cooling
the PTC.
starting voltage after 5
min. for balancing cycle
pressure and cooling
the PTC.
Check the
resistance of
Motor
Compressor.
resistance of
Motor
Compressor.
Check the
resistance of
PTC-Starter.
resistance of
PTC-Starter.
Check OLP.
Check
starting state.
starting state.
7-2 PCB FUNCTION
7-2-1 POWER CIRCUIT
The secondary part of the TRANS is composed of the power supply for the display and relay drive (12Vdc) and that for the
MICOM and IC (5Vdc).
MICOM and IC (5Vdc).
The voltage for each part is as follows.
VA1 is a part for preventing the over voltage and noise. When 385V or higher power is applied, the inside elements are
short-circuited and broken, resulting in the blowout of the fuse in order to protect the elements of the secondary part of the
TRANS.
short-circuited and broken, resulting in the blowout of the fuse in order to protect the elements of the secondary part of the
TRANS.
- 19 -
PART
VA 1
CE 2
CE3
VOLTAGE
220 Vac
12 Vdc
5 Vdc
7-2-2 OSCILLATION CIRCUIT
This circuit is to generate the base clock for calculating time and the synchro clock for transmitting data from and to the
inside logic elements of the IC1(MICOM). Be sure to use the authentic parts since the calculating time by the IC1 may be
changed or it will not work if the OSC1 SPEC is changed.
inside logic elements of the IC1(MICOM). Be sure to use the authentic parts since the calculating time by the IC1 may be
changed or it will not work if the OSC1 SPEC is changed.
7-2-3 RESET CIRCUIT
The RESET circuit is for allowing all the functions to start at the initial conditions by initializing various parts including the
RAM inside the MICOM (IC1) when the power is initially supplied or the power supply to the MICOM is restored after a
momentary power failure. For the initial 10ms of power supply, ‘LOW’ voltage is applied to the MICOM RESET terminal.
During a normal operation, 5V is applied to the RESET terminal. (If a trouble occurs in the RESET IC, the MICOM will not
work.)
RAM inside the MICOM (IC1) when the power is initially supplied or the power supply to the MICOM is restored after a
momentary power failure. For the initial 10ms of power supply, ‘LOW’ voltage is applied to the MICOM RESET terminal.
During a normal operation, 5V is applied to the RESET terminal. (If a trouble occurs in the RESET IC, the MICOM will not
work.)
- 20 -
7-2-4 LOAD DRIVE CIRCUIT
1. Load Drive Condition Check
- 21 -
Load Type
Defrosting Heater
Refrigerator Fan
Measurement Location(IC5)
No.13
No.10
No.12
ON
1V or below
Condition
OFF
12V
Comp,
Freezer Fan Motor
Click on the first or last page to see other GR-S392QVC service manuals if exist.