I have a number of 1980's music keyboards all Korg M1's.
I also have quite a few spares mostly motherboards for the M1.
The problem I have on one board is that it just hisses like a radio that is not tuned in instead of playing the keyboard sounds.
Another motherboard I have just does not produce any sound.
I have tried the boards in more than one keyboard and swapped all the other internal boards over so I am confident that I have narrowed it down to the motherboards.
On the one that hisses I have swapped a couple of capacitors and one transistor but it was purely guess work and it made no difference.
The board that produces no sound I have not touched.
Any ideas?
I also have quite a few spares mostly motherboards for the M1.
The problem I have on one board is that it just hisses like a radio that is not tuned in instead of playing the keyboard sounds.
Another motherboard I have just does not produce any sound.
I have tried the boards in more than one keyboard and swapped all the other internal boards over so I am confident that I have narrowed it down to the motherboards.
On the one that hisses I have swapped a couple of capacitors and one transistor but it was purely guess work and it made no difference.
The board that produces no sound I have not touched.
Any ideas?