IBM 201 manual Power-supply LEDS, Troubleshooting

Table 3. Power-supply LEDS

AC Good	DC Good	Description	FRU/action
LED	LED
Off	Off	No power to system	1.	Check AC power to system.
		or AC problem.
			2.	Power supply
On	Off	Standby mode or DC	1.	Check system board cable
		problem.
				connectors J32, J33, and J35.
				Move jumper on J32’s extension
				cable to pins 2-3 to bypass
				power control. If the DC Good
				LED comes on, press
				Ctrl+Alt+Delete. Watch the
				screen for any POST errors.
				Check the System Event/Error
				Log for any listed problems. If
				the system powers up with no
				errors:
				a.	Power switch assembly
				b.	System board
			2.	Remove the adapters and
				disconnect the cables and power
				connectors to all internal and
				external devices. Power-on the
				system. If the DC Good LED
				comes on, replace the adapters
				and devices one at a time until
				you isolate the problem.
			3.	Power supply
			4.	Power backplane
			5.	System board
On	On	Power is OK.	N/A

Chapter 7. Troubleshooting 49