Samsung MultiXpress K7 Series Service Manual page 400

4. Troubleshooting
► Error Code
S1–2510 / S1–2521
► Error message
MSOK System Failure #S1-2510: Turn off then on.
MSOK Failure: #S1-2521. Call for service
► Symptom
MSOK is not installed properly. / MSOK is defective.
► Troubleshooting method
NOTE
To see the troubleshooting video for this error, click through to the link below.
• S1–2510 : http://tsp.samsung.com/tsp_file/spds/samsungprinter/K7/Webview/EN_K7_S1-2510.html
• S1–2521 : http://tsp.samsung.com/tsp_file/spds/samsungprinter/K7/Webview/EN_K7_S1-2521.html
1) Remove the rear cover.
2) Check if the MSOK is inserted correctly. Remove and reinstall it.
3) If the problem persists, replace the main board.
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