The stock 7805 voltage regulator should be replaced with one that has a higher current rating such as the ST L78S05CV, which is included in each SNES kit.
We also include a 22uF surface mount capacitor which can replace the 1uF capacitor on the 78S05's output for additional improvement. This capacitor is optional and can be used if the vertical line issue still persists after replacing the 7805 voltage regulator. The capacitor is found on the 7805's output circuit, typically footprint 'C61' on the bottom side of the board.
