IBM 7940, Problem Determination And Service Manual

Page: 91 / 160

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 3, “Parts listing, Type 7940 and 7941 servers,” on page 19 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.
Beep code Description Action
Three short beeps Memory error.
1. Reseat the DIMMs.
2. Locate the failing DIMMs:
a. Remove all DIMMs from the server.
b. Beginning with the primary bank of
DIMMs, return one bank of DIMMs to
the server at a time, restarting the
server each time, until the beep code
error returns.
c. Replace one pair of DIMMs at a time in
the failing bank with an identical pair of
known good DIMMs, restarting the
server after each pair, until the beep
code error returns.
d. Replace one DIMM at a time in the
failing pair with an identical known good
DIMM, restarting the server after each
DIMM, to identify the failed DIMM. If the
beep code error remains after you have
replaced both DIMMs, go to step 3b.
e. Repeat steps 2b through 2d until you
have checked all memory banks.
3. Replace the following components, one at a
time, in the order shown:
a. DIMMs
b. (Trained service technician only) System
board
Chapter 5. Diagnostics
73