Dgx-660-too loud

Hello- I have a DGX660 with a continuing problem. Whenever I play the E two notes above middle C it sounds like I am hitting the key with a mallet no matter how easily I touch it. Here is what i have done. Disassembled the keyboard numerous times, cleaned the grey rubber pads, replaced the grey rubber pads with new ones, replaced the middle control board of the keyboard. When I replaced the middle keyboard with a new board I purchased from Syntaur the problem went away for about 6 months. Now I am back to square one. Has anyone else had this problem. The only thing I can say which does not seem related is that I purchased a foot pedal for the keyboard( a good one) anyway it didn’t seem like too long after purchasing and using this the loud sound came. I also used the foot pedal after replacing center electronic control board. I know this should have no effect but its the only weird thing I can add. I bought the piano in 2016 and it plays well other than that. It is out of warranty so I am kind of stuck. It cost me about $800 which I hate to waste but at this time it seems thats whats going on

This issue is on the same key even after replacing the mid mk board?
The pedal would have nothing to do with it.
Maybe Syntaur’s parts are defective…
I would always order the parts direct from Yamaha (unless NLA)
This issue is caused by the circuit board pad (of the key in question) having a bad trace. Sometimes a microscope is required to see the damage. It also could be a small piece of debris (ie dust) in the rubber by the black contacts (dots). The last thing to check is the connecting ribbon cables to make sure there are no wayward wires sticking out of the connectors or doubled up in the same holes.
Good luck!