Light path diagnostics panel

View the controls and LEDs on the light path diagnostics panel. Light path diagnostics LEDs remain lit only while the server is connected to power.

A checkpoint code is either a byte or a word value produced by UEFI and sent to the I/O port indicating the point at which the system stopped during the boot block and Power-On Self Test (POST). It does not provide error codes or suggest replacement components. These codes can be used by IBM Support for more in depth troubleshooting.

To access the light path diagnostics panel, slide the release latch on the front of the operator information panel to the left.

The following table lists the LEDs on the light path diagnostics panel and suggested actions to solve the detected problems.

Follow the suggested actions in the order in which they are listed in the Action column until the problem is solved. If an action step is preceded by "(Trained service technician only)," that step must be performed only by a trained service technician.
LED	Description	Action
None, but the system-error LED is lit.	An error has occurred and cannot be diagnosed, or the IMM has failed. The error is not represented by a light path diagnostics LED.	Check the system-error log for information about the error.
OVER SPEC	The server was shut down due to a power supply overload condition on one of the power channels. The power supplies are using more power than their maximum rating.	If any of the 12v power channel error LEDs (A, B, C, D, E, or 240v AUX) on the system board are lit also. (See System-board LEDs for the location of the 12v power channel error LEDs.) Check the power supply LEDs for an error indication (AC LED and DC LED are not both lit, or the power-supply error LED is lit). Swap power supplies 1 and 2 with each other. If the error follows the power supply, (trained service technician only) replace the failed power supply. If the error remains with the power bay, (trained service technician only) replace the system board. (Trained service technician only) Remove optional devices from the server.
LOG	An error message has been written to the system log	See the system log for details about the error.
LINK	Reserved.
PS	A power supply has failed.	Check the power supply LEDs for an error indication (AC LED and DC LED are not both lit, or the power-supply error LED is lit). (Trained service technician only) Make sure that the failing power supply is correctly seated. (Trained service technician only) Swap power supplies 1 and 2 with each other. If the error follows the power supply, replace the failed power supply. If the error remains with the power bay, (trained service technician only) replace the system board.
PCI	An error has occurred on a PCI bus or on the system board. An additional LED will be lit next to a failing PCI slot.	Check the LEDs on the PCI slots to identify the component that is causing the error. Check the system-error log for information about the error. (Trained service technician only) If you cannot isolate the failing adapter through the LEDs and the information in the system-error log, remove one adapter at a time from the failing PCI bus, and restart the server after each adapter is removed. Call the next level of support.
SP	The service processor (the IMM) has failed.	(Trained service technician only) Remove power from the server; then, reconnect the server to power and restart the server. Update the firmware on the IMM. Call for service.
FAN	A fan has failed, is operating too slowly, or has been removed. The TEMP LED might also be lit.	(Trained service technician only) Replace the failing fan, which is indicated by a lit LED near the fan connector on the system board.
TEMP	The system temperature has exceeded a threshold level. A failing fan can cause the TEMP LED to be lit.	Check the error log to identify where the over-temperature condition was measured. If a fan has failed, replace it. Make sure that the room temperature is not too high. Make sure that the air vents are not blocked. Once you complete the previous steps and feel the root problem that caused a temperature issue is resolved, the iMM interface needs to be rebooted to clear the TEMP indicator. Follow the steps in How to reset/reboot server iMM interface and then return here. If the failure remains, call your next level of support.
MEM	A memory error has occurred.	(Trained service technician only) Replace the failing DIMM, which is indicated by the lit LED on the system board.
NMI	A non-maskable interrupt has occurred, or the NMI button has been pressed.	Check the system-error log for information about the error.
CNFG	A hardware configuration error has occurred.	(Trained service technician only) Check the microprocessors that were just installed to make sure that they are compatible with each other. (Trained service technician only) Replace an incompatible microprocessor. Check the system-error logs for information about the error. Replace any components that are indicated.
CPU	A microprocessor has failed.	(Trained service technician only) Make sure that the failing microprocessor, which is indicated by a lit LED on the system board, is installed correctly. (Trained service technician only) Make sure that the ServeRAID SAS controller is installed and correctly seated. Make sure that the battery for the ServeRAID SAS controller is installed correctly. Call for service.
VRM	Reserved.
DASD	A hard disk drive error has occurred. A hard disk drive has failed or is missing.	(Trained service technician only) Check the LEDs on the hard disk drives and replace the indicated drive. (Trained service technician only) Reseat the hard disk drive backplane cables. (Trained service technician only) Remove and reinstall the hard disk drive backplanes. (Trained service technician only) Replace the hard disk drive backplane for the failing drive or drives. Call the next level of support.
RAID	A RAID controller error has occurred.	(Trained service technician only) Make sure that a RAID controller is installed. Note: The server cannot start without a RAID controller installed. Check the system-error log for information about the error. (Trained service technician only) Reseat the RAID controller.
BRD	An error has occurred on the system board.	(Trained service technician only) Check the LEDs on the system board to identify the component that is causing the error. Check the system-error log for information about the error. (Trained service technician only) Replace any failed or missing replaceable components, such as the battery or PCI riser-card assembly. (Trained service technician only) If a voltage regulator has failed, replace the system board.