LG ARNU Series, Service Manual

Page: 122 / 226

122 Trouble Shooting Guide
Checking Method for Key Components
P
N
U
V
W
3 7 11
16 17 18
P
N
U V W
1
19
Array of IPM Pin
If one of the above articles is not satisfied,
IPM must be inferior and is to be replaced
Internal circuit diagram
Appearance
1. Unplug the +, – terminal of electrolytic capacitor from the P and N terminal of
IPM
2. Set the multi meter to resistance mode
Check and estimate the resistance between each pair of terminal
(P, N), (P, U), (P, V), (P, W), (U, N), (V, N), (W, N), the estimated value should be
large enough to Mega Ohm unit.
3. Set the multi meter to resistance mode
Check and estimate the resistance between each pair of terminal
(3, U), (7, V), (11, W), (16, N), (17, N), (18, N), the estimated value
should be large enough to Mega Ohm unit.
the check point is inside of the screw hole
(U, V, W, N), if check points are plate
face of the terminal, then estimated values are gate resistance.
4. Set the multi meter to diode mode, and estimate between each pair of
terminal (U, P), (V, P), (W, P), (N, U), (N, V), (N, W), the estimated value
should be stable and be in between 0 to 1. (ex: 0.35, 0.46 etc.)
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
2.5 IPM(Integrated Power Module)