Air Conditioner Don't Start

[sfiber]

Hi friends.
I have an air conditioner that doesnt work for years and I need to repair it now. It doesnt have any response after powering up from onboard switch or via remote controller. In photo there is a little rectifier ac-dc converter card and 7805 power regulator.When I measured 7805 output with 7805's ground pin I see 4.99V but when I measured output with ac input reference I see 110.3 V AC. Should I see ac on 7805's output.(Same AC Value on 7805 input pin)

[Kilo Tango]

Doubt it.

Ken

[hermit]

but when I measured output with ac input reference I see 110.3 V AC

I'm not one hundred percent sure what you mean here.  What AC input reference do you mean?  You hooked up your meter between an AC and DC voltage or you switched your meter to AC mode or both?

[sfiber]

I mean;measuring between 7805 output and Notr of AC line with AC mode of DMM.

[Armadillo]

Oh I remember you, the kitchen gas detector guy.

Better be careful, there are the hot ground and the cold ground. Better read up and take the correct ground.
See the shaded demarcation line on the pcb, that's the separation between the danger side and the safer side.

Edit: Any DC voltage there?

Edit: I think its not safe for you, so I will stop from here.