Macbook Air 13" (mid2012) - screen freezes many times a day after El Captain update

[andremarttins]

Here is my Macbook Air basic configuration:

MacBook Air (13-inch, Mid 2012)
Processor: 1.8 GHz Intel Core i5
Memory: 4 GB 1600 MHz DDR3
Graphics: Intel HD Graphics 4000 1536 MB (13.3-inch 1440 x 900)
MAC OSX El Captain 10.11.6 (15G1004)

After the El Captain update, I have 3x, 4x or more times a day a freezed screen. It looks pretty weird. I almost can't work safely now on my Macbook. After the freezes, I have to force shutdown...

Here is a photo of my last freezed screen, this afternoon:

Can this be fixed? Or it's one more of those "you have to buy a new logic board for this Macbook Air" issue?

Thanks a lot for any help, hint or idea on what's going on.

Best,
Andre
Sao Paulo, Brazil