Fujitsu AUXB04GALH Service Manual page 99

Trouble shooting 14
OUTDOOR UNIT Error Method:
Signal Amplifier Auto Address Error
Detective Actuators:
Outdoor unit Main PCB
Forecast of Cause :
1. Signal amplifier power supply defective
3. Signal amplifier auto address wrong setting
Check Point 1 : Check signal amplifier unit power supply
Check signal amplifier unit power supply
OK
Check Point 2 : Check the signal amplifier number connection
Check if more than 8 signal amplifiers (filter mode = off) are connected in a network.
Check if more than 32 signal amplifiers (filter mode = on) are connected in a network.
OK
Check Point 3 : Check the operation of signal amplifier auto address setting
Check if signal amplifier auto address is set at the same time from
multiple outdoor units (master unit)
OK
Check Point 4 : Check noise, momentary open, voltage drop
Check if power supply temporarily stops by outages or if strong noise is generated from
surrounding environment during signal amplifier auto address
Indicate or Display:
E28. 4
Outdoor Unit : E. 2 8. 4
Indoor Unit : No Display
Error Code : No Display
Detective details:
When abnormal answer signal is input during signal amplifier auto address
04-23
*Service tool does not indicate the Error
2. Signal amplifier overconnected
4. Noise, momentary open.