LG ARNU Series, Service Manual

Page: 121 / 226

Service Manual 121
Checking Method for Key Components
Appearance
+
-
~
(W)
~
(V)
~
(U)
1. Unplug the + terminal of electrolytic capacitor from the + terminal of
3phase bridge diode
2. Set the multi meter to resistance mode
Check and estimate the resistance between each pair of terminal (+, -),
(+, ~(U)), (+, ~(V)), (+, ~(W)), (~(U), -), (~(V), -), (~(W), -),
the estimated value should be large enough to Mega Ohm unit.
3. Set the multi meter to diode mode, and estimate between each pair of
terminal (~(U), +), (~(V), +), (~(W), +), (-, ~(U)), (-, ~(V)), (-, ~(W)),
the estimated value should be stable and be in between 0 to 1.
(ex: 0.35, 0.46 etc.)
If one of the above articles is not satisfied,
bridge diode must be inferior and to be replaced
+
-
~
(U)
~
(V)
~
(W)
Internal circuit diagram
In case that the control box is opened and before checking electrical parts,
it should be checked that the LED 01Y (in inverter board, refer to page 172) turned off
(wait 3 minutes after main power OFF), otherwise it may cause electrical shock.
Caution
2.4 3Phase Bridge Diode