• “Error messages” on page 37 • “Beep errors” on page 38 • “No-beep symptoms” on page 40 • “LCD-related symptoms” on page 40 • “Intermittent problems” on page 41 • “Undetermined problems” on page 41 The symptom-to-FRU index in this section lists symptoms and errors and their possible causes. The most likely cause is listed first, in boldface type. Note: Do the FRU replacement or other actions in the sequence shown in the column headed “FRU or action, in sequence.” If replacing a FRU does not solve the problem, put the original part back in the computer. Do not replace a nondefective FRU. This index can also help you determine, during regular servicing, what FRUs are likely to need to be replaced next. A numeric error is displayed for each error detected in POST or system operation. In the displays, n can be any number. If no numeric code is displayed, check the narrative descriptions of symptoms. If the symptom is not described there, go to “Intermittent problems” on page 41. Note: For a device not supported by diagnostic codes in the ThinkPad notebook computers, see the manual for that device. Numeric error codes Table 2. Numeric error codes Symptom or error FRU or action, in sequence 0177 Replace the system board. Bad SVP data, stop POST task—The checksum of the supervisor password in the EEPROM is not correct. 0183 1. Run the ThinkPad Setup program. The settings Bad CRC of Security Settings in EFI Variable. Enter the will be corrected automatically. Then save the ThinkPad Setup program. – The checksum of the Security current settings by pressing F10. settings in the EFI Variable is not correct. 2. Replace the system board. 0187 Replace the system board. EAIA data access error—The access to EEPROM is failed. 0188 Replace the system board. Invalid RFID Serialization Information Area. 0189 Replace the system board. Invalid RFID configuration information area—The EEPROM checksum is not correct. 0190 1. Charge the battery pack. Critical low-battery error 2. Replace the battery pack. 0191 1. Run the ThinkPad Setup program, and then save System Security—Invalid Remote Change requested. current setting by pressing F10. 2. Replace the system board. 0199 1. Run the ThinkPad Setup program. The retry count System Security— Security password retry count will be reset. Then save the current settings by exceeded. pressing F10. 2. Replace the system board. 36 T480 Hardware Maintenance Manual