I have a Casio Casiotone MT-70 that is not functioning. when it is switched on there is a hum from the speaker and nothing else. any help diagnosing the problem would be greatly appreciated, even where to find circuit diagrams and manuals would be very helpful. thank you!
help repairing a Casio casiotone MT-70
- Thread starter ben5
- Start date
happyrat1
Destroyer of Eardrums!!!
I owned one of those 30 years ago. It was my very first electronic 'piano' 
Mine fried after the power supply shorted out. It was a sickness with those units.
Back then it was bricked and I tossed it but nowadays I'd be willing to take a shot at fixing it.
Anyway, first off it will depend on your skill level and the tools available to you.
Step#1 >>> Take a multimeter and check if the power supply is delivering the rated voltage.
Step#2 >>> Check the internals and see if power is reaching the internal chips.
Step#3 >>> depends on what you find with steps 1 & 2
Step#4 >>> try the same tests operating with batteries instead of wall wart.
Gary
Mine fried after the power supply shorted out. It was a sickness with those units.
Back then it was bricked and I tossed it but nowadays I'd be willing to take a shot at fixing it.
Anyway, first off it will depend on your skill level and the tools available to you.
Step#1 >>> Take a multimeter and check if the power supply is delivering the rated voltage.
Step#2 >>> Check the internals and see if power is reaching the internal chips.
Step#3 >>> depends on what you find with steps 1 & 2
Step#4 >>> try the same tests operating with batteries instead of wall wart.
Gary
I owned one of those 30 years ago. It was my very first electronic 'piano'
Mine fried after the power supply shorted out. It was a sickness with those units.
Back then it was bricked and I tossed it but nowadays I'd be willing to take a shot at fixing it.
Anyway, first off it will depend on your skill level and the tools available to you.
Step#1 >>> Take a multimeter and check if the power supply is delivering the rated voltage.
Step#2 >>> Check the internals and see if power is reaching the internal chips.
Step#3 >>> depends on what you find with steps 1 & 2
Step#4 >>> try the same tests operating with batteries instead of wall wart.
Gary
thanks! after testing it with some batteries it started working, I was not using the original power supply and that seemed to be the problem, the wall power connector output is reversed compared to other ones.