Hello there... I have completed the firmware restoration. It worked as the way you suggested. Sadly my button input malfunction still persists. I have also disambled the 3DS XL for fourth times and this time I have disambled the touchscreen to see if there is anything stuck but nothing there.. Also, I have disabled the touch function by removing a black ribbon removing, found that the malfunction still there... So, I am sure its hardware issue. Is there any debugging method to find out what is causing the button input malfunction glitch..? Or is there any other way? Also, there are no dust in any buttons as well as L and R ribbon is okay, there is no visible hardware issue in motherboard.