IBM 2652 Hardware Maintenance Manual - Page 43

Power system checkout Checkout guide To verify a symptom, do the following: 1. Power off the computer. 2. Remove the battery pack. 3. Connect the ac adapter. 4. Check that power is supplied when you power on the computer. 5. Power off the computer. 6. Disconnect the ac adapter and install the charged battery pack. 7. Check that the battery pack supplies power when you power on the computer. If you suspect a power problem, see the appropriate one of the following power supply checkouts: v "Checking the ac adapter" v "Checking operational charging" on page 40 v "Checking the battery pack" on page 40 v "Checking the backup battery" on page 41 Checking the ac adapter You are here because the computer fails only when the ac adapter is used: v If the power problem occurs only when the port replicator is used, replace the port replicator. v If the power-on indicator does not turn on, check the power cord of the ac adapter for correct continuity and installation. v If the computer does not charge during operation, go to "Checking operational charging". To check the ac adapter, do the following: 1. Unplug the ac adapter cable from the computer. 2. Measure the output voltage at the plug of the ac adapter cable. See the following figure: 2 1 (16 - 10 V) Pin Voltage (V dc) 1 +15.5 to +17.0 2 Ground 3. If the voltage is not correct, replace the ac adapter. 4. If the voltage is acceptable, do the following: v Replace the system board. v If the problem persists, go to "Product overview" on page 45. Note: Noise from the ac adapter does not always indicate a defect. General descriptions 39