My MacBook Air keyboard qwerty row has an intermittent fault.

1) you can show Keyboard Viewer in the menuBar using [√] Show input Menu in MenuBar":

then the mouse can be used to click on a Keyboard character on the screen to enter a key.

2) You can hook up "any old USB keyboard". Alphabetic and numeric keys will work fine, Windows modifier keys will be close, buy may be a little different.

executive summary: most keyboard problems that follow a row or "column" are Hardware problems. The keyboards are not fixable, a replacement would be required, or use a wireless or USB keyboard.

Greetings, semdgw.

I see that the top row of the keyboard on your MacBook Air stop working from time to time. Great job on resetting the SMC, I'm happy to help.

If your Apple keyboard doesn't work

Other keys

You might have set an option that changes how your keyboard operates. Choose Apple () menu > System Preferences, and then try these tips:

• In the Accessibility pane, click Speech in the left side. If "Speak selected text when the key is pressed" is selected, deselect it or click Change Key to select another key.
• In the Accessibility pane, click Keyboard. Make sure Enable Slow Keys is turned off. If it's on, you have to hold down a key longer than usual before it's recognized.
• In the Accessibility pane, click Mouse & Trackpad. Make sure Enable Mouse Keys is off. If it's on, pressing keys in the numeric keypad moves the pointer instead of entering numbers.
• In the Keyboard pane, click Input Sources. Make sure that the correct keyboard layout is selected.

You can also see your keyboard's current layout on your Mac's display to make sure that you're using the correct layout:

1. In System Preferences, click Keyboard, then select "Show keyboard and emoji viewers in menu bar."
2. Choose the keyboard icon in your menu bar, then choose Show Keyboard Viewer. You'll see a graphical representation of your keyboard that highlights the corresponding keys you press on your keyboard.

Apple - Support - Product Selection -- If the steps above doesn't point out where the issue is, it's time to contact Apple Support. After selecting this link choose Mac Notebooks > Hardware Issues > Keyboard not working as expected, then select the method you'd like to contact them with.

Take care!