• Code: 820
• Description: Self-Diagnostic Error: CPU
  During the boot monitor program and self-diagnostic, any exception or cutin are not supposed to happen. If these happen, it is defined as SC.
• Causes: • Defective CPU device
  • Defective boot monitor program or selfdiagnostic program

• Code: 821
• Description: Self-Diagnostic Error: ASIC
  ASIC error
• Causes: • Defective controller board

• Code: 822
• Description: Self-diagnostic error: HDD (Hard Disk Drive)
  When the main switch is turned on or starting the self-diagnostic, the HDD stays busy for the specified time or more.
• Causes: • Loose connection
  • Defective HDD
  • Defective controller

• Code: 823
• Description: Self-diagnostic Error: NIB
  6101 - MAC address check sum error
  6104 - PHY IC error
  6105 - PHY IC loop-back error
• Causes: • Defective controller

• Code: 824-1401
• Description: Self-diagnostic Error: NVRAM
  The controller cannot recognize the standard NVRAM installed or detects that the NVRAM is defective.
• Causes: • Loose connection
  • Defective standard NVRAM
  • Defective controller

• Code: 826
• Description: Self-diagnostic Error: RTC/Optional NVRAM
  [1501]: Clock error
  [15FF]: RTC not detected
• Causes: • RTC defective
  • NVRAM without RTC installed
  • Backup battery discharged

• Code: 827
• Description: Self-diagnostic Error: RAM
  [0201: ]Verification error
  [0202]: Resident memory error
• Causes: • Loose connection
  • Defective SDRAM DIMM
  • Defective controller

• Code: 828
• Description: Self-diagnostic Error: ROM
  [0101]: Boost lap code error
  The boot monitor and OS program stored in the ROM DIMM is checked. If the check sum of the program is incorrect, this SC code is displayed.
• Causes: • Defective ROM DIMM
  • Defective controller