HIC-1 board redesign and improvement

Almost all components have arrived. I started to prepare for the new board's testing by putting the original HIC board into a "socket". But that was easier said then done. Desoldering the HIC board was pain in the @ss. It appears that the original pins were not only soldered on both sides of the motherboard, but they were also soldered to both sides of the HIC board. And the ground polygons were very big. So, I had to use the soldering iron to remove the board's ground pins. Better to cut it out and then remove the pins from the board with a soldering iron and tweezers. Here's a pic of the prepared mobo:

Panasonic FS-A1 motherboard is not double sides so it's not difficult to remove it. It's not necessary to cut the pins if you have a good desoldering pump.

That ground plane also seems to act like an EMC shield does it not? Will you add it to your version?

You are right, FS-A1 doesn't have HIC-1 board. It looks like but it's not the same.

Two remarks:

1. The HIC-1 board is above the mainboard and tracks pass underneath it, those tracks emit the electro magnetic signals which can be picked up by tracks on the HIC-1 board.
2. The HIC-1 board is used in many different machines, so even if there is no issue in your FS-A1F it may be completely different in e.g. a Sony HB-F1, e.g if tracks are moving in different directions (up-down vs. left-right).