IBM 7940, Problem Determination And Service Manual

Page: 139 / 160

Solving undetermined problems
If the diagnostic tests did not diagnose the failure or if the server is inoperative, use
the information in this section.
If you suspect that a software problem is causing failures (continuous or
intermittent), see “Software problems” on page 97.
Damaged data in CMOS memory or damaged BIOS code can cause undetermined
problems. To reset the CMOS data, clear the CMOS memory, and override the
power-on password (see “Resetting passwords” on page 117). If you suspect that
the BIOS code is damaged, see “Updating the firmware” on page 15.
Check the LEDs on all the power supplies (see Power-supply LEDs). If the LEDs
indicate that the power supplies are working correctly, complete the following steps:
1. Turn off the server.
2. Make sure that the server is cabled correctly.
3. Remove or disconnect the following devices, one at a time, until you find the
failure. Turn on the server and reconfigure it each time.
v Any external devices.
v Printer, mouse, and non-IBM devices.
v Each adapter.
v Hard disk drives.
v CD or DVD drive
v Memory modules. The minimum configuration requirement is 1 GB (two 512
MB DIMMs in DIMM slots 5 and 6).
v Microprocessor 2 (if installed)
4. Turn on the server.
If the problem is solved when you remove an adapter from the server but the
problem recurs when you reinstall the same adapter, suspect the adapter; if the
problem recurs when you replace the adapter with a different one, suspect the riser
card.
If you suspect a networking problem and the server passes all the system tests,
suspect a network cabling problem that is external to the server.
Problem determination tips
Due to the variety of hardware and software combinations that can be encountered,
use the following information to assist you in problem determination. If possible,
have this information available when requesting assistance from Service Support
and Engineering functions.
v
Machine type and model
v
Microprocessor or hard disk upgrades
v Failure symptom
– Do diagnostics fail?
– What, when, where, single, or multiple systems?
– Is the failure repeatable?
– Has this configuration ever worked?
– If it has been working, what changes were made prior to it failing?
– Is this the original reported failure?
v
Diagnostics version
Chapter 5. Diagnostics
121