LENOVO N581 – HOW TO CHECK THE BATTERY PACK - HOW TO TEST THE BATTERY CHARGER – HOW TO REMOVE THE KEYBOARD – HOW TO REPLACE THE BATTERY

Lenovo N581 – How to check the battery pack - How to test the battery Charger – How to remove the Keyboard – How to replace the battery

Lenovo N500: How to verify the symptoms 
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”
“Checking operational charging”
“Checking the battery pack”
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.
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:

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.
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.
Perform operational charging. If the battery status indicator or icon does not light on, remove the battery pack and let it return to room temperature. Reinstall the battery pack. If the charge indicator or icon is still off, replace the battery pack.
If the charge indicator still does not light on, replace the system board. Then reinstall the battery pack. If it is still not charged, go to the next section.
Checking the battery pack
Battery charging does not start until the Power Meter shows that less than 95% of the total power remains; under this condition the battery pack can charge to 100% of its capacity. This protects the battery pack from being overcharged or from having a shortened life.
To check your battery, move your cursor to the Power Meter icon in the icon tray of the Windows taskbar and wait for a moment (but do not click it), and the percentage of battery power remaining is displayed. To get detailed information about the battery, double-click the Power Meter icon.
Note: If the battery pack becomes hot, it may not be able to be charged. Remove it from the computer and leave it at room temperature for a while. After it cools down, reinstall and recharge it.
To check the battery pack, follow the steps below:
1. Turn off the computer.
2. Remove the battery pack and measure the voltage between battery terminals
1 (+) and 7 (-). See the following figure:

3. If battery output voltage is less than +3.9V DC, the battery is damaged, replace it. If battery output voltage is less than +9V DC, perhaps the battery has entered into over discharge protection mode, pre-charge the battery with AC, replace the battery if battery capacity cannot be charged over 0% within 2 hours.

4. If the battery output voltage is more than +9V DC, measure the resistance between battery terminals 5 and 7. The resistance should be 4 to 30 KΩ. If the resistance is not correct, replace the battery pack. If the resistance is correct, check the system board function.

DISASSEMBLING PROCEDURE 

Battery pack

Unlock the manual battery latch 1. Holding the spring-loaded battery latch in the unlocked position 2 , remove the battery pack

Keyboard

Remove the three screws 1.

Loosen the keyboard with fingers in the direction shown by arrows 2.

Lift the keyboard a little 3 , and then detach the connector.