Trouble Shooting - Hitachi RAS-07G4 Service Manual

TROUBLE-SHOOTING
No cooling
Operates by setting the service
switch to forced cooling?
YES
Return the service switch to
"Normal".
Set the remote controller to an
operation status and press the ON/
OFF button.
Is the level LO (approx. 0.5V)
between driver IC501 pin
relay and 0V?
NO
Is voltage normal between Blue wire
and Red wire of Indoor DC Fan
Motor
NO
No operation at all.
*1
NO
1) Current fuse
2) Varistor
3) Power switch
4) Thermal fuse for
Terminal board
10 power
Power relay abnormal
YES
Compressor does not turn at LO.
Indoor fan motor or
*3
YES
*1 Before using the service switch,
disengage and engage the plug. Do not
operate the remote controller.
Check the following parts and replace if faulty
Remove and check the continuity across.
Check whether the appearance is blackish or not.
The resistance must be infinite. *2
Check the continuity between contacts.
(102°C) Continuity across
check the electric parts and replace if abnormal.
*2 Before checking the varistor, detach a terminal.
Q903 abnormal
– 63 –
→
If there is no continuity,
Replace Power relay