Kitchenaid refrig kfis20xvms2 control panel has blue screen, no functions, some lights when a key is held down.

That is usually on the model/serial sticker located inside refrigerator section at top. Hopefully the control came with instructions on how to enter service mode and enter code. Otherwise, the unit will not function. Good Luck

Faulty PCB

Locate the Fn (Function) key on your keyboard. It may be on the bottom left side with dark blue letters. Locate the two "brightness" keys near the top of the keyboard. These will be in the "F" keys, possibly if F6 and F7. They should have little sun pictures or something similar to indicate brightness. Hold down the Fn key while pressing F7, or whichever "F" key your laptop uses to increase brightness. Tap F7 repeatedly until you reach the desired brightness. Fn must be held down as you continue to tap. Hope this helps.

On most laptops, there are 2 blue-tinted pictures that may looks like light bulbs or suns located on 2 of the function keys (F1, F2, etc.) that stand for increase and decrease brightness. If you hold the "Fn" key, and start tapping the increase brightness key, the screen should turn brighter. Otherwise, you may be able to adjust screen brightness from Windows, by going to power options (control panel or right click the battery icon in the task bar) or by customizing your desktop (control panel or right click on the desktop).

You can use the function keys to try brightening the screen, but it doesn't seem like it would help. Hold down the function key (the blue "Fn" key next to the Windows logo key) and press the up arrow in the lower right corner of the keyboard repeatedly. Every time you press the arrow (with the function key held down) it should brighten the screen by one degree.

If the backlight and inverter have both been replaced, the problem is most likely either the screen itself, or a pinched cable somewhere in the connection between the screen and the motherboard or video card. If you know how to take the laptop apart, you can check for pinched cables or harnesses -- if you don't see any, it's most likely the screen.

you need to hold down ctrl and function on the left side of your keyboard, and then hit the shift key on the right side of your keyboard. Then let go of right shift while still holding down the control and function keys, and then hit right shift again.

these blue keys are french keys. if you change your keyboard settings to english US or UK, it will get rid of the blue functions, but for some reason, they tend to turn themslves back on again after time. Most likely due to automatic updates followed by an auto restart. Also, I find that the issue only arises if I am in my hotmail account.....no issue in Word docs.

Sometimes the brightness is on the arrow keys hit the Fn or function key and press down on the arrow to dim the light or press up on the arrow key to increase brightness

You'll need a 2 button combination for this fix. All the cat did was adjust the screen brightness. Look at the bottom of your keyboard on the left side for a button that has Fn in light blue -this is the Function key. It controls the other keys that have a second function on them also in blue. On your right side, you'll see keys that look like a sun or lightbulb depending on your model. By holding down the Fn key and tapping either key, you will increase or decrease the brightness of the screen.
Let me know how this works for you and rate this tip accordingly. Thanks for using Fixya.com.

I started having the same problem with my KBMC140HSSO. You cannot see the error codes without disassembling the control panel (the codes are on another display that covered by the front panel). After doing so I found the error code to be F2, E3 which is "Key held down too long, or key shorted". I am ordering a replacement keypad and will report back if this fixes the problem.