Toshiba HFC R407C Service Manual page 53

Diagnostic procedure for check code
Check code
[99]
Remote controller serial
signal circuit alarm
Are A, B, C internal wires normal?
Yes
Is there a connection error?
No
Is group operation performed?
No
Is SW01 set to No. 1?
Yes
Does the indoor unit operate?
Yes
Troubleshooting
Status of air conditioner
Indoor unit stops
No
Yes
Yes
Is SW01 set to No. 1 on
the master unit?
Is SW01 duplicated?
No
No
Does serial LED (Green)
D15 on the indoor PC board
Does serial LED (Orange)
D14 on the indoor PC
board flash?
Operation cause
1. Remote controller circuit connection error.
2. Duplicated indoor No.1 units.
3. Remote controller error.
4. Indoor PC board error.
No
Yes
Yes
No
Yes
flash?
No
Yes
No
Check connection of wiring.
Check indoor PC board.
If defective, replace.
Set SW01 to 1.
Correct switch SW01.
Make unit set-up No.1.
Check indoor PC board.
If defective, replace.
Check remote controller.
If defective, replace.
53