Hey all
So my MB goes out of tune every 20Žand it drifts quite noticeably between octaves. I read the touchtones and tried to calibrate but, i can a rather decent calibration between C2 and C3 even though C3 is always a bit sharper by around 50 cents. Then C1 and C4 are completely off, flat by 200 cents or so. It is imposible to calibrate between C1 and C2, they never reach a close point. I basically opened the gate and sent voltages from the keyboard, i then adjusted with a plastic flathead, adjusted pitch on the higher octave and then slope for the lower one...
Are there any other trims inside? or does it seem like something more complicated?