Fujitsu Error Code 1b

[piewie]

Hello everyone.
I have a Fujitsu under ceiling or cassette type split the model number on the condensing unit is AOT54LJBYL. On the indoor control panel the error code is 0:16 now this could be error code 16 or error code 1b. I picked up that 16 is HP trip but there is no HP switch on the outdoor unit so I suppose it is 1b. I found a sheet on the net that mentions this as a problem with the condensing fans or drive unit/controller. Can anyone elaborate on this for me or perhaps point me to some further reading? Any help would be appreciated. Many Thanks

[install monkey]

http://www.mediafire.com/view/?db08w35r3dd2aph fujitsu manuals are cr*p unless u need dimensions of the unit

[install monkey]

check outdoor unit led's on pcb

[oldmanriver]

1b is outdoor fan motor error. Either an issue with one of the DC Fan Motors or the main control (IPM) board. Always possible that a faulty DC fan motor has damaged the board too.

[ozairman]

As oldman says its an outdoor fan motor fault, check the flashing led on the outdoor board and count it to see if its the upper or lower motor, other wise reset the unit and watch for the motor that does not spin!. Quite likely the board will be OK as this error is triggered by a lack of feedback signal from the motor. If the fan motors have shat themselves in a big way it will normally blow the hidden DC power supply fuse on the main inverter board, which causes a 01 serial signal error.
The metal cased fan motors could be more better described as hand grenades with the pin out the later ones in the white plastic cases are much more reliable.
Dont try to disconnect the fan motors with the unit powered up, they and the boards do not like it.
To check the fan motors use Diode check mode on your multimeter to check between the Red-Black in forwards and reverse direction and White-Black leads of the motor in forwards-reverse direction. If you get the same reading in both direction or a short circuit then the motor is u/s.
The top motor is Fan motor 1 and plugs into CN800, the lower one is Fan motor 2 and plugs into CN801.
On the Board if you look at it from the top you will see Pin 1 marked, the test points and also wire colours on the plug are
1 = (Red) 300-380VDC main power
2 = Blank
3= Blank
4 = (Black) DC ground reference
5 = (White) 15 VDC control power
6 = (Yellow) Speed signal from board ~5vdc when motor is running
7 = (Brown) Feedback input from fan motor to PCB

With the fan motor disconnected if you can measure the three voltages mentioned above with reference to Pin 4 then the board sounds OK.