Lenovo ThinkCentre M77 Hardware Maintenance Manual (HMM) - ThinkCentre M77 - Page 74

Message/Symptom FRU/Action Incorrect memory size during POST 1. Run the Memory tests 2. Memory Module 3. System Board "Insert a Diskette" icon appears with a known-good diagnostics diskette in the first 3.5-inch diskette drive. 1. System Board 2. Diskette Drive Cable 3. Network Adapter Intensity or color varies from left to right of characters and color bars 1. Display 2. Video adapter (if present) 3. System Board No power or fan not running 1. See "Hard disk drive boot error" on page 49. Non-system disk or disk error-type message with a known-good diagnostic diskette. 1. Diskette Drive 2. System Board 3. Diskette Drive Cable Other display symptoms not listed above (including blank or illegible display) 1. Display 2. System Board Power-on indicator or hard disk drive in-use light not on, but computer works correctly 1. Power switch/LED assembly 2. System Board Printer problems 1. Printer 2. System Board Program loads from the hard disk with a known-good diagnostics diskette in the first 3.5-inch diskette drive 1. Run Setup and check Startup sequence. 2. Diskette Drive 3. Diskette Drive Cable 4. System Board 5. Power Supply RPL computer cannot access programs from its own hard disk. 1. If network administrator is using LCCM Hybrid RPL, check startup sequence: a. First device - network b. Second device - hard disk 2. Hard disk drive RPL computer does not RPL from server 1. Check startup sequence 2. Check the network adapter LED status Serial or parallel port device failure (system board port) 1. External Device Self-Test OK? 2. External Device 3. Cable 4. System Board 70 ThinkCentre Hardware Maintenance Manual