Fujitsu AOY90TPAMF

[andy c]

Hello all,
I have a Fujitsu AOY90TPAMF which is showing no faults at the controller, but the condensing unit wont function in heating or cooling. The outdoor pcb has Led1 flashing constantly, and Led5 is flashing six times. I have tried to get a service manual from Fujitsu tech, but it still hasn't turned up. I tried to force the heating mode via the dip switch, but still nothing functioned. Any ideas welcomed, and a service manual would be gratefully accepted. I think the pcb may be goosed, but without being able to check anything, i don't want to say for sure. I weren't impressed with the Fujitsu technical helpline. Cheers, Andy C.

[andy c]

A quick update, i managed to find a service manual, and after a bit of reading and checking, found the outdoor pcb is goosed. A new pcb is on order, 7 - 10 days from Spain. Fujitsu tech helpline weren't much help when i finally got through to them.

Andy C.

[andy c]

We have replaced the outdoor board with a brand new one, and we are getting exactly the same fault. If anyone can shed some further light, i would be most obliged. Thanks in advance. Andy C.

[nike123]

We have replaced the outdoor board with a brand new one, and we are getting exactly the same fault. If anyone can shed some further light, i would be most obliged. Thanks in advance. Andy C.

In order to work properly, PCB board need to have all power supply voltages.
First check that voltages are correct.
Also check for possible noise (electromagnetic) sources.

[andy c]

Thanks Nike, we have carried out several checks to ensure the power supplies are correct. There is little chance of noise/ interference within the cabling, although we haven't checked. I have just ordered a new signal pcb, and will be changing it in the near future, based on advice given by a Fujitsu engineer.

[nike123]

Outdoor unit circuit board error 1

1. Error occurrence condition:

Communication between control printed circuit board and communication printed circuit board of outdoor unit isn't performed correctly.

2. Relevant operation

1) Current operation is continued. Error is displayed on LED of outdoor unit.
2) If error is kept for 90 seconds since error occurs, new communication error (1F) occurs.

3. Clearance

The communication between control printed circuit board and communication printed circuit board of outdoor unit is performed correctly.

Possible causes:

1. Effect of extraneous noise:

1. When power is turned off, and turned on again:
1) If error doesn't occur, printed circuit board is normal. Then, remove noise sources near outdoor unit.
2) If error occurs again, remove noise sources and take measure with the following countermeasure No.2 and 3.

2. Outdoor unit communication PC board insertion is faulty.

2. Check the insertion of outdoor unit communication printed circuit board.

3. Printed circuit board is faulty.

3. Replace printed circuit boards with the following procedure, and check the operation.
(1) Replace outdoor unit communication printed circuit board
(2) Replace outdoor unit control printed circuit board

Your only "fault" in this is for not following procedure exactly as said in manual. It could save you one (much more expensive) PCB.

[andy c]

Thanks again Nike, we have tried on numerous occasions to obtain a service manual for this unit, but Fujitsu being Fujitsu, cannot, or are unable to send us a copy of one. We shall carry out the necessary checks to ensure there are no noise issues.
It is a site we have recently inherited, which has had countless faults on the system over the years, mainly due to poor installation (mainly leaks and moisture).