21
Diagnostic Chart
(for 12k Models)
If, after energizing the unit, no indicator is lit and the unit cannot be operated, see the following chart.
TROUBLESHOOTING
Be sure all the wires (including power wires and connection wires)
are OK
Install good ones
Check for AC (208-230V) power supply outputs to
outdoor control board
Check if AC (208-230V) exists at primary coil
of transformer (18K & 24K models only)
Outdoor
control board
is Defective
Check if AC 12V and AC 35V (+5%) exist at secondary coil
of transformer in the outdoor control board
Take off the secondary plug of transformer, and then check if AC
12V and AC 35V (+5%) exist at secondary coil of transformer
Outdoor
control board
is Defective
Transformer is defective
Check if DC 35V exists between
2 & 3 on the indoor terminal
and DC 12V between 3 & 4
Check if DC 35V exists
at CN6 and 12V
at CN3
Indoor
control board
is Defective
Uncertain problem on
Indoor control board.
Change it & check again.
Yes
Yes
Yes
No
No
No
No
Yes
Yes
No
Yes
Yes
No
