Fujitsu Aircon PCB Board Failure - E1 Coms Error

tunzafun001 on 11/06/2022 - 21:05
Last edited 11/06/2022 - 21:06

Hi all,

Anyone know what component commonly dies on Fujitsu aircons PCB boards? Seems like these boards die a lot, but rediculously expensive for what they are.

I have an AOT45 ducted unit.

I used Fujitsu's technical service guide and worked out the fault is on the outdoor unit (should be fluctuating 120v DC on the signal wire.. Its a constant 13v)

Have ruled out the Diode Bridge, ACTPM, fan motors, compressor and EV coil and all fuses. Everything measured up at Fujitsu's specifications.

So basically all components are good. But the E01 coms error remains.

Nothing stands out as burnt or popped on the boards. No dud solder joints or blown tracks.

Interesting facts if it helps -

The error appeared months ago, turning it off/ on fixed it for a few months. Now it wont go away.

In cooling mode and fan mode the indoor fan still runs. In heating mode, nothing runs.

Cheers.

Electrical & Electronics

Comments

  • Muzeeb on 11/06/2022 - 21:12
    +3

    Dear diary?

  • SF3 on 11/06/2022 - 21:15
    -1

    OP has confused us with Fujitsu iFixit.

    With the advancement of STEM, they’ve worked out the formula for planned obsolescence.

    We have a newer model on offer, it’s more shiny than your model.

  • tunzafun001 on 11/06/2022 - 22:02

    Im sure this will be pretty common issue and there will be a fridgey or two on here who have a clue.

    The soloution these days is bin it and buy a new one…when all thats needed is a single transistor , diode or similar replaced.

  • c64 on 11/06/2022 - 22:18

    might be a blown mosfet/triac/diode. use a multimeter in diode mode to check the diodes and mosfets. discharge any big caps first :)

    • tunzafun001 on 12/06/2022 - 00:48

      Cheers, yeah I think it must be something to do with the SMPS. None of the fuses have blown, so shouldn't be too catastrophic.

      $1500 for the PCB. I'll be much happier swapping out a mosfet.

  • Typical16-bitEnjoyer on 12/06/2022 - 15:01
    -1

    Maybe try this website rather than OzB…. https://www.refrigeration-engineer.com/forums/showthread.php…

  • AndyC1 on 12/06/2022 - 15:11

    Looks like OP may have posted on a more relevant thread on the 3-Jun-2022, but discarded solutions from previous in the thread:
    https://forums.whirlpool.net.au/archive/2430684

    Good luck.

    • tunzafun001 on 12/06/2022 - 15:59

      Indeed.. I have now tested everything and the PCB is definitely faulty. The generic soloution being replace the inverter PCB $1500, power pcb $300, ACT module $300 and maybe a fan motor or two. ..might as well buy a whole new unit.

      However the actual PCB problem is likely a single $3 triac or similar.

      Sadly these days its turf the lot, buy another.

      Figured ozbargain is more likely to have people who will chose the $3 approach.

      • AndyC1 on 12/06/2022 - 16:03

        Oz bargain has way way less people who can do board level repairs compared to whirlpool users.

        • tunzafun001 on 13/06/2022 - 19:37

          Guess so.. but Ozbargain has far more frugal repairers.

          Only need one who has done it before.

    • tunzafun001 on 14/06/2022 - 11:09

      Cheers, I haven't looked at the thermistor yet, unlikely, but can only try.

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