Fujitsu inverter AST9LSACW Red light prob

[Porks]

I have done a search and found I have same problem as "Oz_Sparky" 12 months ago....the indoor unit blinks 5 red lights whilst green continuously blinks.
Installation sheet says.."Outdoor unit circuit board error or miswiring between o/d and i/d unit".
Have done the test circuit thing and erased memory as previous advice but to no avail.
It just took15 minutes of operation for red /green fault to activate, during which time the outdoor unit..stopped after 3 mins, restarted 5 mins later, stopped 3 mins later, started 2 mins later, stopped 2 mins later.
A service agent I spoke to, suggested being prepared to pay $1000 for PCB, yet eBay has new unit equivalent for $840.
Seeking best advice; perservere with problem finding, or bite the bullett and install new unit of same size.
I see no reason why a new unit could not use existing electrics and plumbing thus saving on installation ?
Appreciate any advice...thanks..Porks

[Porks]

Just adding to above, I have noticed also that the Outdoor unit is showing a red blinking light 6 times..fan was not running..thanks