Display on control nothing running

[Paul a/c]

Hi guy been called out to a Fujitsu system today I've got a ARY45TLAMA indoor and a a AOY90TPA3L outdoor . Control seem lock nothing would happen powered down still the same swapped control had mode change temp change fan speed but can not turn off once on , tried swapping indoor PCB and still the same . No fault codes and no operation at all , any one had this before

[frank]

Just looking at the model numbers it looks like you have got a mismatched system and need another ARY45TLAMA indoor unit.

Without looking up the model numbers, i think you have a twin split connected as a pair.


Could be mistaken...or under the influence :D Only joking, I've only had a half of orange juice.....

[Paul a/c]

Yeah your right I've got two indoor units the same models , but nothing happening with them , no faults showing outdoor unit has seen better days , they are on R407C gas , not sure how old they are . Any one got any pointers
thanks paul

[Brian_UK]

There isn't another interface or interlock attached to the control circuit is there?

[Tayters]

Hi Paul,

That's a big multi system, the forerunner to their VRF back in the day.
The fan is controlled by another relay board with 4 wires. 12 or 14 V DC on red and black turn on a solid state relay which puts out 240V on blue and white.
If the fan stays on high then this is a sure sign of a dodgy relay board but confirm the signal voltage first.
Apart from the strainers getting gummed up that's about all I know about them. Hope it helps!

[Paul a/c]

Hi guys been back to site found that fuse is blown on slave power board on indoor unit replaced 4A fuse blow again , not sure if faults on indoor or outdoor unit any one had this fuse blow before