If key programer CN900 screen became black and white . Please check follow ways how to fix it:

Step 1: First connect CN900 Key Programmer with computer and power by USB wire

Step 2: First download : CN900_LOADER V3.10

Then decompressing file and save it

Step 3: Click .

You will see in front of Fast there marked hook

Step 4: Remove the Hook in front of Fast.

Step 5: After remove the Hook in front of Fast then press Update button. After then CN900 Key Programmer and update with computer together.

Step 6: After key programer CN900 finished update with computer then will recover as follow:

Remark 1:If update one time the CN900 auto key programmer still not recover then try as above ways again and again till it recover.

Remakr 2:If during update CN900 Key Programmer and appear a window which need you choose COM port. Then you need to choose a correct COM port. If you do not know which is correct COM port then operate as follow steps:

First right click my computer and choose property

And then choose Hardware.

And then choose device manager

And then find port (COM and LPT) and click + then will see follow ports

And then take CN900 USB wire out from computer then check the port (COM and LPT)again:

Checking the difference between connect with CN900 USB wire with computer and take out CN900 USB wire from Computer:

Then you will see when connect with CN900 USB wire with computer then will see .

After take out CN900 USB wire from computer then disappear.

So you need to choose .

Notice:When choose COM port not must be . Different computer have different case. It depend on that when you connect CN900 USB wire with computer and take out USB wire from computer which port ( COM) appear and disappear therefore that port (COM ) you need to choose.