Carrier 38QUS012D8S - Page 129

Troubleshooting
Electrical Control System 127
2.4.4.7. F4 Malfunction
Malfunction conditions
Main PCB chip does not receive feedback from EEPROM chip
Possible causes
● Installation mistakes
● Faulty PCB
Yes
Replace the outdoor main PCB
Replace the outdoor main PCB
Power off, then restart the
unit 2 minutes later. Does a
problem still exist?
Power off, then restart the
unit 2 minutes later. Does a
problem still exist?
Outdoor EEPROM malfunction
Outdoor EEPROM malfunction
F4- Display
F4- Display
EEPROM: An electrically erasable programmable read-only memory whose contents can be erased and
reprogrammed using a pulsed voltage.
2.4.4.8. F5 Malfunction
The same as E3 in indoor unit.