Lenovo ThinkCentre M50 Hardware Maintenance Manual (HMM) - Page 114

Message/Symptom FRU/Action ″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. Riser card 4. Network Adapter Intensity or color varies from left to right of 1. Display characters and color bars 2. System Board No power or fan not running See "Power Supply Errors" on page 70. Non-system disk or disk error-type message with a known-good diagnostic diskette. 1. Diskette Drive 2. System Board 3. Diskette Drive Cable 4. Riser card 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 1. Power Supply light not on, but computer works correctly 2. System Board 3. LED Cables Printer problems Printer Program loads from the hard disk with a known-good diagnostics diskette in the first 3.5-inch diskette drive 1. Run Setup 2. Diskette Drive 3. Diskette Drive Cable 4. System Board 5. Riser card 6. 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 Serial or parallel port device failure (adapter 1. External Device Self-Test OK? port) 2. External Device 3. Cable 4. Alternate Adapter 5. System Board Some or all keys on the keyboard do not work 1. Keyboard 2. Keyboard Cable 3. System Board 108 Hardware Maintenance Manual