SC669

What it means

Controller or engine EEPROM/NVRAM checksum failed. Config, counters, or serial data is unreadable.

Likely causes

• Corrupt NVRAM
• Controller
• Engine EEPROM
• Bad firmware flash

1. 1Backup if you canIf the panel still works, SP5-824-001 NVRAM upload to SD. If it does not, you will be rebuilding.
2. 2Download / replaceTry NVRAM download (SP5-825-001) from the last known-good SD. If it still fails, replace the NVRAM/controller and restore. Re-enter serial, counters, and destination with the SMC / serial-set procedure.
3. 3FirmwareA half-finished firmware job is a classic 669. Re-flash the matched set from SD.

Parts to have on the truck

• NVRAM
• Controller

Related procedures

• NVRAM backup and restore

  SD upload/download so a controller or NVRAM swap does not wipe serial and counters.

• GW+ controller recovery

  Hardware keys, DIP, and SD recovery when SOP will not boot (819/820/672 loops).

Related codes