Korg Forums

[ddpianoman]

My M50 seems to be working ok although sometimes, I don't know why, it has a distorted output. I have cleaned it out (contacts etc) and it usually sounds great, but sometimes it will have distorted output. Doesnt happen often, but I have no idea whats going on. Its through headphones or speakers either one. BUT that is not the main problem I have right now. I want to reset it to factory settings but when I go to global, and try to access the basic menu on the top where it should say load factory presets (etc), it does not show me anything, no dropdown menu. It does click when I touch it, but nothing happens. I have noticed on the drop downs don't respond they way they did either. I cant hit ok or cancel (no response) so I have to hit the enter button. Cant slide from page to page either...WTF? Is my screen shot, or maybe dirty? If so can it be cleaned internally or do I need a new screen? any ideas? Love my M50 and this is P!@#$%^ me off!

[voip]

There is a chance that it might be a power supply issue, causing distortion and a change in the screen calibration.

Does the display flicker when wiggling the power supply connector in the M50?

The first thing to check is the M50 power supply. Does the power supply produce the rated output voltage? It should be 12V , or thereabouts. This can be measured with a multimeter connected to the centre and outer ring of the coax power plug whilst it is unplugged. This will measure the open circuit voltage. It would be better to also measure the in-circuit voltage, which means taking the cover off the M50 and measuring the voltage where the power connector comes into the M50, whilst the keyboard is switched on.

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[StephenKay]

For the touch screen, try the "Touch Panel Calibration" option in the Global > Basic Page Menu.
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Stephen Kay - KARMA Developer • Karma-Lab - karma-lab.com