korg internal device-system error ff00012...etc.

[bambus14]

Hi, i having same problem korg freeze and show me some internal code error on the screen. Do you anybody known whats that mean? and how much cost repair this at korg service?
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....i check up system with keys on start up, test bypass midi and test ok, with midi ports - check system error occured...not sure whats exatctly it is. If some midi, or crack ram...please any help. THX