Korg M1 motherboard fault, no sound.

shirreff · Post by **shirreff** » Wed Jun 21, 2017 10:13 pm

Hi,
I've got 2 M1's. One fully working the other not producing sound so I swapped parts and narrowed it down to the mother board sadly.
Does any one have any ideas on what might be the problem?

Mellontikos · Post by **Mellontikos** » Wed Jun 28, 2017 3:47 am

shirreff wrote:Hi,
I've got 2 M1's. One fully working the other not producing sound so I swapped parts and narrowed it down to the mother board sadly.
Does any one have any ideas on what might be the problem?

Those old boards are known for faulty filter caps on the analog side of the DAC.

Could be the DAC, could be the OP Amps, or it's filter caps, or both. You might not be able to see physical damage.

Not producing sound at all could be caps completely toast, either leaking or dry. Got pics of the insides?

shirreff · Post by **shirreff** » Wed Jun 28, 2017 4:28 am

Hi,
Not got any pics at the moment but I cannot see any damage. I've had a good look. I'll send some pics asap.

shirreff · Post by **shirreff** » Wed Jun 28, 2017 7:08 am

https://drive.google.com/folderview?id= ... jVYZGRjU0k
Not sure how to upload pics on here so I've put them in my Google drive.
See if you can view from there.[/url]

voip · Post by **voip** » Wed Jun 28, 2017 7:42 pm

Looking at the pics, there's nothing that really stands out as a potential problem, apart from in IMAG0184.jpg, near the top of the image, IC36 has what looks like possibly a piece of fine wire amongst its pins, which would cause problems, although it's more likely to be be a fabric fibre catching the light.

Is it possible the backup battery has been changed but the factory data not restored?

.

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Korg M1 motherboard fault, no sound.

Korg M1 motherboard fault, no sound.

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