RAM Checksum

RAM Checksum Error

Otis · 400 Elevator

What does RAM Checksum mean?

Indicates that the machine setup information stored in RAM has been corrupted. This can lead to incorrect machine operation or configuration issues, as no test is available to verify the checksum internally.

Common Causes

  • Corruption of machine setup information.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Measure the supply voltage at the main control board input terminals to confirm it is within specified operational limits.

  2. 2

    Inspect the NVRAM backup battery (if present on the main control board) for correct installation, corrosion, and measure its voltage.

  3. 3

    Verify the current machine configuration parameters displayed on the HMI or diagnostic tools against the latest system backup or manufacturer specifications.

  4. 4

    Inspect all data and power cables connected to the main control board for secure seating and absence of damage.

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Verified technical data. Last updated: March 2026

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