strange behaviour with external monitor

[koerk]

Hello everybody.

My 2012 MBA 13" behaves very strangely since Mavericks. When I am on the go or at work I use the MBA itself, at home at my desk I have a Dell Monitor that I plug in to via Thunderbolt-HDMI Adapter and HDMI to DVI Cable. Since the following yet only occured when plugged in to the monitor, I think it might have to do with it:

strange behaviour #1:
When I have MBA and monitor running and do a restart or wake up from sleep, the monitor often stays black and OS X only shows on the MBAs screen. I can keep on unplugging and plugging in over and over again, the monitor is not recognized. Only a complete restart MIGHT help with that. "detect monitors" under monitor settings doesn't help either.

strange behaviour #2:
the following happened to me twice for now (while restarting because of #1). When I restarted my MBA, it hangs itself up during the startsound and keeps repeating the sound infinitely. While it does that there is a crackling sound besides the sound itself, like an old broken speaker
I decided to call Applecare where the employee led me through resetting PRAM and SMC. After that my MBA booted as usual, I thought I was fine.

But today, the problem reoccured.

Do you have ANY idea what this could be?
Please help me.

 

[kch50428]

Sounds like something to run by a GenuisBar specialist at an Apple Store.

 

[koerk]

You might be right...
Unfortunately it isn't so easy to reproduce and doesn't happen at all when not plugged in to a second screen...

 

[koerk]

Went to the apple store today. After showing them a video I took of said phenomenon they tried to hook up an external display (asus ) but somehow they couldn't make it work. Funny!
Either way, he just said that it can only be the logic board that might be defective and he offered me to change the logic board within my warranty. Apple care saved me 350? again which might be the repurchase price, don't know.

Thanks for your help, I thought i should share how things worked out.

 

[kch50428]

Good to see you got a solution to the issue...

 

[koerk]

Actually it is not a solution after all. Like I said they changed the MLB of my Air but my external monitor showed that strange behavior again today, this drives me insane. I couldn't get a signal to the dell display, nothing worked.

Do you think this could be the monitors fault?

 

[koerk]

Couldn't get it to work today either, no signal on the monitor. At first!

I changed the Hdmi-DVI cable in favor of a VGA and it works now. Could this be caused by the mini display port to Hdmi adapter? The cable cannot be broken because it works on my girlfriend's windows laptop.