Lenovo 3779 Computer Hardware User Manual


 
v Follow the suggested actions in the order in which they are listed in the Action column until the problem
is solved.
v See Chapter 7, “Parts listing, ThinkServer RD220 Type 3729, 3779, 3797, and 3798,” on page 231 to
determine which components are customer replaceable units (CRU) and which components are field
replaceable units (FRU).
v If an action step is preceded by “(Trained service technician only),” that step must be performed only by a
trained service technician.
System event/error log message Action
+12v critical over voltage fault
1. If the OVER SPEC LED on the light path diagnostics panel is
lit, or any of the four power channel error LEDs (A, B, C, or D)
on the system board are lit, see the entries about
power-channel error LEDs in “Solving power problems” on
page 143. (See “Power-supply LEDs” on page 50 for the
location of the power channel error LEDs.)
2. If the actions in “Solving power problems” on page 143 do not
identify a defective component, complete the following steps:
a. Remove the power supplies.
b. Replace the power supplies one at a time, restarting the
server each time, to isolate a failing power supply.
c. If the server fails to start, replace the power backplane.
Restart the server.
d. If the server fails to start, (trained service technician only)
replace the system board.
+12v critical under voltage fault
1. If the OVER SPEC LED on the light path diagnostics panel is
lit, or any of the four power channel error LEDs (A, B, C, or D)
on the system board are lit, see the entries about
power-channel error LEDs in “Solving power problems” on
page 143. (See “Power-supply LEDs” on page 50 for the
location of the power channel error LEDs.)
2. If the actions in “Solving power problems” on page 143 do not
identify a defective component, complete the following steps:
a. Remove the power supplies.
b. Replace the power supplies one at a time, restarting the
server each time, to isolate a failing power supply.
c. If the server fails to start, replace the power backplane.
Restart the server.
d. If the server fails to start, (trained service technician only)
replace the system board.
12v planar fault
1. If the OVER SPEC LED on the light path diagnostics panel is
lit, or any of the four power channel error LEDs (A, B, C, or D)
on the system board are lit, see the entries about
power-channel error LEDs in “Solving power problems” on
page 143. (See “Power-supply LEDs” on page 50 for the
location of the power channel error LEDs.)
2. If the actions in “Solving power problems” on page 143 do not
identify a defective component, complete the following steps:
a. Remove the power supplies.
b. Replace the power supplies one at a time, restarting the
server each time, to isolate a failing power supply.
c. If the server fails to start, replace the power backplane.
Restart the server.
d. If the server fails to start, (trained service technician only)
replace the system board.
Chapter 5. Diagnostics 137