Lenovo U300E manual Power system checkout, Checking the AC adapter, Checking operational charging

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General checkout

Power system checkout

To verify a symptom, follow the steps below:

1.Turn off the computer.

2.Remove the battery pack.

3.Connect the AC adapter.

4.Make sure that power is supplied when you turn on the computer.

5.Turn off the computer.

6.Disconnect the AC adapter and install the charged battery pack.

7.Make sure that the battery pack supplies power when you turn on the computer.

If you suspect a power problem, see the appropriate one of the following power supply checkouts:

•• “Checking the AC adapter ” on page 21

•• “Checking operational charging” on page 21

Checking the AC adapter

You are here because the computer fails only when the AC adapter is used.

•• If the power-on indicator does not turn on, check the power cord of the AC adapter for correct continuity and installation.

•• If the computer does not charge during operation, go to “Checking operational charging”.

To check the AC adapter, follow the steps below:

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:

Pin

Voltage (V DC)

 

 

1

+20

 

 

2

0

2

1

Note: Output voltage for the AC adapter pin No. 2 may differ from the one you are servicing.

3.If the voltage is not correct, replace the AC adapter.

4.If the voltage is acceptable, do the following:

•• Replace the system board.

•• If the problem continues, go to “Lenovo IdeaPad U300e” on page 27. Note: Noise from the AC adapter does not always indicate a defect.

Checking operational charging

To check whether the battery charges properly during operation, use a discharged battery pack or a battery pack that has less than 50% of the total power remaining when installed in the computer.

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Contents Lenovo IdeaPad U300e First Edition Oct Copyright Lenovo 2011. All rights reserved Contents About this manual Safety information General safety Electrical safety Lenovo IdeaPad U300e Hardware Maintenance Manual Safety inspection guide Grounding requirements Safety notice Safety notices multilingual translationsLenovo IdeaPad U300e Hardware Maintenance Manual Safety information Lenovo IdeaPad U300e Hardware Maintenance Manual Safety information Lenovo IdeaPad U300e Hardware Maintenance Manual Safety information Laser compliance statement Safety information Strategy for replacing FRUs Important service informationImportant notice for replacing a system board Strategy for replacing a hard disk driveImportant information about replacing RoHS compliant FRUs General checkout What to do first Following are not covered under warrantyChecking the AC adapter Power system checkoutChecking operational charging Lenovo IdeaPad U300e Hardware Maintenance Manual Restoring the factory contents by using OneKey Recovery Related service informationPower-on password PasswordsSupervisor password Screen blank mode Power managementSleep standby mode Hibernation mode Lenovo IdeaPad U300e SpecificationsSpecifications Status indicators Status indicatorsHotkey Function key combinationsScrew notices FRU replacement noticesRemoving and replacing an FRU Removal steps of base cover Base coverLenovo IdeaPad U300e Hardware Maintenance Manual Removal steps of battery pack Battery packRemoval steps of hard disk drive Hard disk driveRemoval steps of Dimm DimmRemoval steps of PCI Express Mini Card for wireless LAN PCI Express Mini Card for wireless LANWhen installing Removal steps of fan assembly and heat sink assembly Fan assembly and Heat Sink assemblyLenovo IdeaPad U300e Important notices for handling the system board System boardRemoval steps of system board Lenovo IdeaPad U300e Hardware Maintenance Manual Removal steps of speakers and microphone Speakers and microphoneRemoval steps of the speakers and microphone Removal steps of LCD unit LCD unitWhen installing Removal steps of keyboard and keyboard bezel Keyboard and keyboard bezelM2 × 3 mm, flat-head, nylok-coated Black M2 × 5 mm, flat-head, nylok-coated Black Lenovo IdeaPad U300e Hardware Maintenance Manual Front view LocationsBottom and Left-side view Right-side viewParts list Overall No. FRU FRU no Parts list-OverallLenovo IdeaPad U300e Hardware Maintenance Manual Keyboard Parts list-KeyboardLenovo IdeaPad U300e Hardware Maintenance Manual Miscellaneous parts Parts list-Miscellaneous partsAC adapters Parts list-AC adaptersParts list-3-pin power cords Power cords145000525 145000553 UK 2PIN Parts list-2-pin power cordsLenovo IdeaPad U300e Lenovo IdeaPad U300e Hardware Maintenance Manual Trademarks