Understanding the Buttons and LEDS, and how to connect them to the MCP23017 board

This is an 8-button matrix configuration, where multiple buttons share a common cable or row, while their differentiation is achieved through columns. For instance, buttons 1 and 2, which correspond to play and pause functions, are assigned to Row 1. Pressing button 1 activates Column 1, while the pause function is associated with Column 2.

And hopefully, with a bit of luck, the corresponding LED should light up when a button is pressed.

In a nutshell: even though there are 8 buttons you only have 6 wires.

Once you have delicately detached the button and LED ribbon cables from the old circuit board, the next step involves separating and extending the individual wires using your proficient soldering skills (don't forget to use the heat shrinks).

Both ribbon cables are connected to the MCP23107 board: LEDs are on row A (PA0-PA7) and the Rows and Columns are on row B (PB0-PB5)