Chosen Solution
My Yamaha psr 85 has no sound. The keyboards turns on, screen is also working but no sound from any key or even beat/demo keys. Help please. Speaker might not be an issue because I’ve tried connecting external speakers directly at the solderings inside the keyboard, still no sound.
Hi, You might have to use a DMM (Digital Multimeter) and test if there is any voltage present on the keys. Normally with most electronic keyboards a voltage is passed through the operated key(s) to the CPU which then selects which sound to play depending on which input lead to the CPU it is on. As none of the keys work it seems as though the power rail for this particular section of the keyboard may be the problem. Unfortunately I cannot find a service manual for your keyboard to be more helpful. If there is no voltage present on the keys you may have to go back to the power supply board in the keyboard and find all the different power rails that it has to determine which one is not working. As it is only low voltage (9VDC) it is safe for you personally to test, i.e it is not life threatening as it would be if it was working on mains power, BUT do not short out or ‘bridge’ across any connections with the meter’s test leads as you can still cause component damage anyway. Good luck.
