IBM 86655RY Hardware Maintenance Manual - Page 251

Undetermined problems You are here because the diagnostic tests did not identify the failure, the Devices List is incorrect, or the system is inoperative. Notes: 1.A corrupt CMOS can cause undetermined problems. 2.A faulty I2C Bus can cause undetermined problems. Check the system error log for any I2C Bus errors; see "I2C bus fault messages" on page 239. Check the LEDs on all the power supplies, see"Power supply LED errors" on page 225. If the LEDs indicate the power supplies are working correctly, return here and do the following: 1. Power-off the computer. 2. Be sure the system is cabled correctly. 3. Remove or disconnect the following (one at a time) until you find the failure (power-on the computer and reconfigure each time). Any external devices Surge suppressor device (on the computer) Modem, printer, mouse, or non-IBM devices Each adapter Hard disk drives Memory-Modules (Minimum requirement = 512 MB (4x128 MB DIMMs)) Note: Minimum operating requirements are: a. 1 Power Supply b. Power Backplane c. Processor/PCI Board (with pins 2 and 3 on J23 connected together to bypass the power switch; default is pins 1 and 2) d. I/O Legacy Board (Verify that connection to Processor/PCI Board is secure.) e. 1 Microprocessor and VRM f. 3 Terminator Cards g. Memory Modules (with a minimum of 1 bank of four 128 MB DIMMs (4x128)) 4. Power-on the computer. If the problem remains, suspect the following FRUs in the order listed: Power Supply Power Backplane Processor/PCI Board I/O Legacy Board Notes: 1.If the problem goes away when you remove an adapter from the system, and replacing that adapter does not correct the problem, suspect the Processor/PCI Board, then the I/O Legacy Board. 2.If you suspect a networking problem and all the system tests pass, suspect a network cabling problem external to the system. Symptom-to-FRU index 241