Fujitsu (ASTB09LDC/12LDC) fault codes/lights

[briggsi]

Hi

I've read a number of threads on the www from people with similar issues, and seen some listings of fault light sequences but cannot seem to get a precise match!

Wall mounted air con working fine and has been for 4 years since installation. that is until yesterday.

Turned on indoor unit walked away when I came back into the room something not right. Noticed the red 'operation' light not on but green 'timer' light flashes intermittently. On closer inspection realised that the green light was flashing twice every 10 secs or so. Had to lower temp to 22 degree C to get any semblance of cooling to happen [sister unit in next room working a treat]. Turned the unit off (via the control device) and on turning it back on noticed that the red 'operation' light did come on albeit very briefly before the green 'timer' resumed its flash sequence.......

Help pls - any suggestions as to what's up with the unit (either indoor, or the outdoor one, or both??)

[Tayters]

G'day Cobber.

2 flashes is comms error.

Check the interconnect and all fuses are fine.
Select cooling test run and check 240V between L and N outdoors.
If there then check between comms and N - should be 70-120V fluctating. If hovering around 50V then chances are only one unit is communicating. You can disconnect comms wire and check on DC volts between the comms and N. One way gives + the other - both 50-100V DC. This way you can tell which unit is communicating and which isn't. Might need to power off then on to reinitiate comms.

Most often no comms from outdoors. If this is the case double check fuses (and any on PCB) power down for 2 mins, disconnect comp, fan EEV and power up. If comms has returned repeat process with one component plugged in at a time to see which is taking the power to the board out (search posistor for it's operation).

If you find fan motor faulty search here for checking a BLDC motor. If no comms with everything unplugged then suspect PCB but also be aware fan motor will need checking, also check comp windings to earth, coils of EEV head, inverter IC is screwed down to heat sink.

No monkeying about with fan motor connector unless outdoor powered down for a good 2 mins as stored charge on PCB will let rip all sorts of agro otherwise.

10053
10054

Hope that make sense!
Cheers,
Andy.