I have an old air conditioner that probably already around 5 years old and it has gone through many experience of ups and downs but it's fine - I used to call the technician to fix in the past but after what i saw and learnt most of the time actually they are not required although sometime they are. Today i have just experiencing the green and red LED light flash at the same time and then the red will keep flashing / blinking after that and the outdoor compressor unit won't turned on because of it - and the red light just keep flashing. The last time was the yellow / orange light problem. Having such problem is very frustrating especially in hot sunny day - and i couldn't afford calling a technician just to fix a small issue like that with hefty price to pay for.
But the good news is sometimes things work in a magical way to save the situation. And the simplest of thing that I thought won't work actually fixed the problem just like that. So what i did was turned off the aircond unit with the remote control and turn off the power switch where the york air conditioner is plugged in. Then take off the filter and rinsed it until clean. Once that done put back the filter and turn on the switch - then use the remote control to turn it on.
By then again i saw the green LED light started to flash / blink and followed by the red LED light. That almost convinced that trick won't work. But after a while the red flash stopped and the green light start to light up constantly and there goes the compressor motor starting to run. And that's it - it fixed again.