Power Supply Problems; Beep Symptoms; Post Error Codes - Lenovo ThinkCentre M70a Hardware Maintenance Manual

Error
The boot sector on the startup drive is corrupted.
The drive is defective.

Power supply problems

If you suspect a power problem, use the following procedures.
Check/Verify
Check the following for proper installation.
• Power cord
• On/Off switch connector
• On/Off switch power supply connector
• System board power supply connectors
• Microprocessor connection
Check the power cord for continuity.
Check the power-on switch for continuity.

Beep symptoms

Beep symptoms are tones or a series of tones separated by pauses (intervals without sound) during POST.
The following table describes the beep symptoms.
Beep symptom
2 short beeps: common POST error
3 short and 1 long beeps: DRAM memory error

POST error codes

Each time you turn on the system, it performs a series of tests that check the operation of the system and
some options. This series of tests are called the Power-On Self-Test, or POST. POST checks the following
operations:
• Some basic system-board operations
• Memory operation
• Video operation
FRU/Action
The drive must be formatted. Do the following:
1. Attempt to back up the data on the failing hard disk
drive.
2. Using the operating system programs, format the
hard disk drive.
Replace the hard disk drive.
FRU/Action
Reseat connectors
Power cord
Power-on switch
FRU/Action
Common POST error code. See the detailed failure
information in "POST error codes" on page 35.
Perform the following actions in order:
1. Make sure that the memory modules are properly
seated in the memory slots.
2. Replace the memory modules.
3. Replace the system board (for trained service
personnel only).
.
Chapter 4 Service checkout and symptom-to-FRU index
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