"I have a Pumpkin Android 4.4 car stereo and it worked perfect. Today I wanted it on, but it stuck on boot logo. I tried  pressing the Reset button and disconnecting the car battery, it remains unchanged. What should I do?"  If your Android 4.4 head unit stuck on boot logo or is required to update the MCU file, then you need to update in the Android system's recovery mode. Here's the guidance for reference:

enter the Pumpkin Android 4.4 car stereo recovery mode

 

Step 1

First of all, please insert the firmware card into the head unit's GPS slot.

Step 2

Then press and hold Power button. Meanwhile, you need to use a sharp tool to short press RST button.

Step 3

Release the head unit's power button after it beeps 3 times. And short press its power button again, you'll enter the Android system's update interface.

Step 4

Press the power button to select "" option. After that, try to enter the recovery mode and choose the "recovery system from back up". And it will update from the SD card.

Also, there's a video instruction for reference: https://www.youtube.com/watch?v=Vtfwfh0Olu4&feature=youtu.be