Repairing a Kawai PN300 digital piano - Replacing the Pads for muffled keys - Part 4

Part 4
My attempt to fix a faulty Kawai PN300. It is an old Digital Piano around the year 2000, It still sounds pretty good for its age. I got the piano at a very good price due to the faults. So I tried my hand at fixing the Piano to restore the piano to its former glory.
Most of the piano worked but the faults were:
1. Some 6 keys in the last 2 octaves were not working at all i.e. 2x C, E, G#.
2. The piano also had some very soft sounding keys as well. They sounded almost muffled when hitting the key as they did not keep sustain every time but randomly played softly.
3. Some stuck keys.
4. Some keys were not level.
The fix was to replace all the disintegrating rubber and plastic pads as seen in the video. Next was to find what was causing the 6 keys to not work at all. Some corroded pads and traces were found which stopped the lower keys getting the required signal.
This 8 part series was a fun hobby fix and I hope there is some useful information in these videos that can help or guide others with similar piano problems.
Please feel free post questions below