Lenovo ThinkPad T495, Hardware Maintenance Manual

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Chapter 3. General checkout
This chapter presents following information:
• “What to do first” on page 25
• “Checkout guide” on page 26
• “Power system checkout” on page 28
Some descriptions in this chapter might not apply to your particular computer.
Before you go to the checkout guide, be sure to read the following important notes.
Important notes:
• Only certified trained personnel should service the computer.
• Before replacing any FRU, read the entire page on removing and replacing FRUs.
• When you replace FRUs, it is recommended to use new nylon-coated screws.
• Be extremely careful during such write operations as copying, saving, or formatting. Drives in the computer
that you are servicing sequence might have been altered. If you select an incorrect drive, data or programs might be
overwritten.
• Replace a FRU only with another FRU of the correct model. When you replace a FRU, ensure that the model of
the machine and the FRU part number are correct.
• A FRU should not be replaced because of a single, unreproducible failure. Single failures can occur for a variety
of reasons that have nothing to do with a hardware defect, such as cosmic radiation, ESD, or software errors.
Consider replacing a FRU only when a problem recurs. If you suspect that a FRU is defective, clear the error log and
run the test again. If the error does not recur, do not replace the FRU.
• Be careful not to replace a nondefective FRU.
What to do first
When you return a FRU, you must include the following information in the parts exchange form or parts return
form that you attach to it:
1. Name and phone number of service technician
2. Date of service
3. Date on which the machine failed
4. Date of purchase
5. Failure symptoms, error codes appearing on the display, and beep symptoms
6. Procedure index and page number in which the failing FRU was detected
7. Failing FRU name and part number
8. Machine type, model number, and serial number
9. Customer's name and address
Note: During the warranty period, the customer may be responsible for repair costs if the computer damage
was caused by misuse, accident, modification, unsuitable physical or operating environment, or improper
maintenance by the customer. Following is a list of some common items that are not covered under warranty
and some symptoms that might indicate that the system was subject to stress beyond normal use.
Before checking problems with the computer, determine whether the damage is covered under the warranty
by referring to the following list:
The following are not covered under warranty:
• LCD panel cracked from the application of excessive force or from being dropped
• Scratched (cosmetic) parts
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