ive never really been to this part of ecoustics......normally stay in car audio.....but i have a panasonic SA-AK640......and whenever i turn it on it says F61.....and cuts off.....wat does this mean?
It means it has a fault and needs service parts F61 for servicing and repair. take it to your nearest panasonic deqaler or electronics technician and they should be able to fix it.
