Lenovo ThinkPad L520 Hardware Maintenance Manual - Page 98

System board assembly, Screw quantity, Color, Torque

Page 98 highlights

11 2 2 2 3 Step 1 2 Screw (quantity) M2 × 3 mm, flat-head, nylon-coated (2) M2 × 5 mm, flat-head, nylon-coated (3) Color Black Black Torque 0.181 Nm (1.85 kgfcm) 0.181 Nm (1.85 kgfcm) 2020 System board assembly Important notices for handling the system board: When handling the system board, bear the following in mind. • The system board has an accelerometer, which can be broken by applying several thousands of G-forces. Note: Dropping a system board from a height of as little as 6 inches so that it falls flat on a hard bench can subject the accelerometer to as much as 6,000 G's of shock. • Be careful not to drop the system board on a bench top that has a hard surface, such as metal, wood, or composite. • If a system board is dropped, you must test it, using PC-Doctor for DOS if the system supports PC-Doctor for DOS, to make sure that the HDD Active Protection System™ still functions. Note: If the test shows that the HDD Active Protection System is not functioning, be sure to document the drop in any reject report, and replace the system board. • Avoid rough handling of any kind. • At every point in the process, be sure not to drop or stack the system board. • If you put a system board down, be sure to put it only on a padded surface such as an ESD mat or a corrugated conductive surface. If the system supports PC-Doctor for DOS, after replacing the system board, run PC-Doctor for DOS to make sure that the HDD Active Protection System still functions. The procedure is as follows: 1. Place the computer on a horizontal surface. 2. Run Diagnostics ➙ ThinkPad Devices ➙ HDD Active Protection Test. Attention: Do not apply physical shock to the computer while the test is running. For access, remove these FRUs in order: • "1010 Battery pack" on page 59 92 Hardware Maintenance Manual

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2
1
1
2
2
3
Step
Screw (quantity)
Color
Torque
1
M2 × 3 mm, flat-head, nylon-coated (2)
Black
0.181 Nm
(1.85 kgfcm)
2
M2 × 5 mm, flat-head, nylon-coated (3)
Black
0.181 Nm
(1.85 kgfcm)
2020 System board assembly
Important notices for handling the system board:
When handling the system board, bear the following in mind.
The system board has an accelerometer, which can be broken by applying several thousands of G-forces.
Note:
Dropping a system board from a height of as little as 6 inches so that it falls flat on a hard bench can subject
the accelerometer to as much as 6,000 G's of shock.
Be careful not to drop the system board on a bench top that has a hard surface, such as metal, wood, or composite.
If a system board is dropped, you must test it, using PC-Doctor for DOS if the system supports PC-Doctor for
DOS, to make sure that the HDD Active Protection System
still functions.
Note:
If the test shows that the HDD Active Protection System is not functioning, be sure to document the drop
in any reject report, and replace the system board.
Avoid rough handling of any kind.
At every point in the process, be sure not to drop or stack the system board.
If you put a system board down, be sure to put it only on a padded surface such as an ESD mat or a corrugated
conductive surface.
If the system supports PC-Doctor for DOS, after replacing the system board, run PC-Doctor for DOS to make sure that
the HDD Active Protection System still functions. The procedure is as follows:
1. Place the computer on a horizontal surface.
2. Run
Diagnostics
ThinkPad Devices
HDD Active Protection Test
.
Attention:
Do not apply physical shock to the computer while the test is running.
For access, remove these FRUs in order:
“1010 Battery pack” on page 59
92
Hardware Maintenance Manual