I have sometimes answers (work/ not work) from three out of eight sensors on my Roland PAD-80. I opened the casing and when I triggered them from the backside, all are working! It seems to have also two extra sensors inside, connected, but when I triggered these, nothing occurs.I wanna know how to remove the pads and if I can use the two spare sensors to replace the faulty ones. Thanks!

Audio Players & Recorders - Roland - Spd-S Sampling Percussion Pad System