Vintage Synth Explorer Forums

hey guys, my korg ms10 was working alright until one day, i accidentally fell asleep and left it on. and when i woke up, no sound was coming from it anymore. the red light that pulses/blinks just stays on all the time now...i've tried pretty much everything short from opening her up, but i'm not quite sure what i should be looking for. any suggestions from more seasoned korg ms10 users?

thanks...

If you can check the power supply for the correct voltages...It's a bit tricky if you have no experience.

Well,
MS 10 regulation is +15/-15v. If this was a power problem, the LED would be off, right? (D29 blinks using +15v... means the 18v is working).
Did you try the initial gain input? See if the output section is working.
External signal input?
No sound at all? No static/hum when the adsr is on? It usually goes FFFfffff... when the realase is activated.
CV/trig out? See if the keybord section sends controls.

You need to do that kind of tests, to have an idea of where the problem can be coming from.
Let us know.

If the lfo light is always on it' makes me wonder about the power supply....Anyway it's normal to start from the power supply.
try the last post ..plus Check the noise outs on the patch bay..?

MG use a 4558 as a sorta ramp generator.
If diode D29 doesn't blink, means pin 1 of IC 9 doesn't change state.
I could blame IC 9 (4558).

OR
It blinks so fast, that we can't see it blink, then i would check for D19/D18 shortcuts.

The best thing to measure would be the two MG outs with an oscilloscope. See what the oscillation looks like.

What I don't really get is how could it mute the whole synth. It feeds the VCF after all. A MG shortcut might take VCF down to zero? I don't know.

Let us know.

Don't forget the keyboard gate, could be a simple explanation maybe

Yes it does feel like an op amp problem....

Hybrid88 wrote:Don't forget the keyboard gate, could be a simple explanation maybe

Yes. Sadly the gate doesn't make the MG blink.