LG MULTI V 5 Manual Book page 43

Error No. Error Type Error Point
Communication error The indoor unit did not re-
between IDU and ceive the signal from ODU
ODU (Gen 2) over 3 min continuously.
05
Communication The indoor unit did not
error between IDU receive the signal from IDU
main and IDU local local modem over 3 min
modem (Gen4) continuously.
The indoor unit did not
Communication error
receive the signal from
237 between IDU and
ODU local modem over 3
ODU local modem
min continuously.
The indoor unit did not
Communication error
receive the signal from
238 between ODU mo-
outdoor unit packet over 3
dem and ODU PCB
min continuously.
Error diagnosis and countermeasure flow chart
▒
Error diagnosis and countermeasure flow chart for indoor unit local modem
▒
Communication speed setting Is the Red LED on IDU modem
between IDU and ODU is 9600bps?
Yes
Is the Red LED on IDU modem
No
Did the sensor work well?
(refer to picture)
Yes
Check the connector to Main PCB
Check again after power reset.
No
Is the yellow LED on IDU modem
Check the main PCB power status
blinking for some period?
Change the local modem PCB
if found that the modem is defect.
084
_TROUBLE SHOOTING GUIDE BOOK
Main Reasons
1. IDU PCB or ODU PCB defect
2. Communication line defect
1. IDU PCB or IDU Modem PCB defect
2. Communication line defect
1. IDU or ODU or Modem PCB defect
2. Communication line defect
1. IDU/ODU/Modem PCB defect
2. Communication line defect between
IDU and ODU modem
No
Check the connector to Main PCB
Change the local modem PCB
always OFF?
Yes
Do auto addressing again and check
No
the status after finished the auto
always OFF?
addressing
• Local IDU Modem
Connector to main PCB
For 9600 bps comm., the red LED will always turn on.
For 1200 bps comm., the red LED will always turn off after power
reset and 3 min. later
* The communication speed can be set by dip switch in ODU.
When the indoor unit is sending the signal to other unit, this LED will
be flickering.
If the LED is always off, please check below.
1) Check the connector between local modem and main pcb.
2) Do auto addressing from ODU if the communication speed is
1200 bps.
→ In case of 1200 bps, indoor unit will not response when
there's no address.
RS485 Bus connector to other modem or ODU
• Local IDU Modem
For 9600 bps comm., the red LED will always turn on.
For 1200 bps comm., the red LED will always turn off after
power reset and 3 min. later
* The communication speed can be set by dip switch in ODU
When the outdoor unit is sending the signal to IDU, this
LED will be flickering.
If the LED is always off, check the connector between local
modem and main PCB.
Connector to main PCB
Error No. Error Type Error Point
Indoor unit EEPROM Error occur in EEPROM
09
error of the Indoor PCB
Error diagnosis and countermeasure flow chart
▒
- Replace the indoor unit PCB, and then make sure to perform Auto addressing and input the address of
central control
Main Reasons
1. Error developed in communica-
tion between the micro- processor
and the EEPROM on the surface of
the PCB.
2. ERROR due to the EEPROM damage
085
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