I believe some Acer Aspire 5251/5551G/5551 laptops might have a 3G card installed under this cover.
The keyboard secured by six spring loaded latches on the top.
In order to unlock the keyboard you’ll have to push the latch into the case with a small screwdriver and at the same time lift up the keyboard a little bit.
After all latches pushed in, you should be able to lift up the keyboard.
Turn it over and place upside down on the palmrest.
Now you can access the keyboard cable connector.
You’ll have to unlock the connector and release the cable.
Here’s how to unlock the keyboard connector.
Move the brown locking tab about 1-2 millimeter towards the touchpad (away from the screen).
The locking tab must stay attached to the connector base.
On the following picture you see the same connector in the unlocked position.
After the connector is unlocked you can pull the cable from the connector.
Remove the keyboard.
Remove all screws from the bottom.
Remove seven screws securing the top cover assembly:
1. Power button cable.
2. Left speaker cable.
3. Right speaker cable.
4. Touchpad cable.
You disconnect the power button cable and touchpad cable the same way you disconnected the keyboard cable.
Slide the brown locking tab about 1-2 millimeters to the shown direction.
After the connector is unlocked, pull the cable.
Lift up and remove the top cover assembly.
Under the top cover assembly you can get access to the following internal laptop components:
– Cooling fan.
– CMOS battery (soldered to the motherboard).
– USB board.
– Card reader board.
– DC jack harness.
Disconnect four cables from the motherboard.
Remove one screw securing the motherboard.
Here’s how to unplug the video cable connector.
By the way, in order to remove the motherboard it’s necessary to remove the wireless card which is located on the bottom.
It’s not necessary to disconnect antenna cable from the wireless card. Just remove one screw securing the wireless card and pull it from the slot. You can leave it connected to the antennas, just be careful not to damage them.
Lift up the right side of the motherboard and remove it from the base.
There is one more cable you’ll have to disconnect before removing the motherboard completely.
It’s the power jack cable which is located on the bottom side of the motherboard.
Remove the motherboard from the base.
On the other side of the motherboard you can get access to the cooling fan.
It’s easy to replace the fan. Just remove two screw securing the fan and disconnect fan cable from the motherboard.
After that you should be able to replace the fan with a new one.
The DC power jack located in the upper left corner of the base.
It looks like in order to remove and replace the DC jack harness it will be necessary to lift up the left display hinge. Shouldn’t be a problem though.
For the screen removal instructions check out this guide (disassembly steps 21-29), it should be similar.
Всё! Ноутбук разобран. Сборка происходит в обратном порядке, если у вас возникнут сложности вы всегда можете обратиться к специалистам.