Lenovo N 500 Service Manual

Supervisor password 
A supervisor password (SVP) protects the system information stored in the BIOS 
Setup Utility. The user must enter the SVP in order to get access to the BIOS Setup 
Utility and change the system configuration. 
Attention:   If the SVP has been forgotten and cannot be made available to the 
servicer, there is no service procedure to reset the password. The system board 
must be replaced for a scheduled fee. 
How to remove the hard-disk password 
Attention: 
 If User only mode is...

Power management 
Note: Power management modes are not supported for APM operating system. 
To reduce power consumption, the computer has three power management modes: 
screen blank, sleep (standby), and hibernation. 
Screen blank mode 
If the time set on the “Turn off monitor” timer in the operating system expires, the 
LCD backlight turns off. 
To put the computer into screen blank mode, press the Lenovo Care button and 
use the ThinkVantage® Productivity Center. 
To end screen blank mode and resume...

Hibernation mode 
In hibernation mode, the following occurs: 
v   
 The system status, RAM, VRAM, and setup data are stored on the hard disk. 
v 
 
 The system is powered off.
To
 cause the computer to enter hibernation mode, do any of the following: 
v   
 Press the Fn+F12 keys. 
v 
 
 If you are using the ACPI operating system and have defined one of the 
following actions as the event that causes the system to go into hibernation 
mode, perform that action. 
– 
 
 Closing the lid. 
– 
 
 Pressing the...

Symptom-to-FRU index 
This section contains following information: 
v   
 “Numeric error codes” 
v 
 
 “Error messages” on page 38 
v 
 
 “No-beep symptoms” on page 39 
v 
 
 “LCD-related symptoms” on page 40 
v 
 
 “Intermittent problems” on page 41 
v 
 
 “Undetermined problems” on page 41
The
 symptom-to-FRU index in this section lists symptoms and errors and their 
possible causes. The most likely cause is listed first, in boldface type. 
Note: Do the FRU replacement or other actions in the sequence...

Table 1. Numeric error codes (continued) 
Symptom or error FRU or action, in sequence 
0232
Extended
 RAM error— Extended RAM fails 
at offset nnnn. 
1.   
 DIMM. 
2. 
 
 System board. 
0250
System
 battery error—System battery is 
dead. 
1.   
 Charge the backup battery for more 
than 8 hours by connecting the ac 
adapter. 
2. 
 
 Replace the backup battery and run BIOS 
Setup Utility to reset the time and date. 
0251
System
 CMOS checksum bad— Default 
configuration used. 
1.   
 Charge the backup...

Error messages 
 Table 2. Error messages 
Symptom or error FRU or action, in sequence 
Unsupported memory. DIMM. Make sure to use supported 
memory. 
Device address conflict. 1.   
 Load “Setup Defaults” in the BIOS 
Setup Utility. 
2. 
 
 Backup battery. 
3. 
 
 System board. 
Allocation error for device. 1. 
 
 Load “Setup Defaults” in the BIOS 
Setup Utility. 
2. 
 
 Backup battery. 
3. 
 
 System board. 
Failing bits: nnnn. 1. 
 
 DIMM. 
2. 
 
 System board. 
Invalid system configuration data. 1....

No-beep symptoms 
 Table 3. No-beep symptoms 
Symptom or error FRU or action, in sequence 
No beep, power-on indicator on, LCD blank, 
and no POST. 
1.   
 Make sure that every connector is 
connected tightly and correctly. 
2. 
 
 DIMM. 
3. 
 
 System board. 
No beep, power-on indicator on, and LCD 
blank during POST. 1. 
 
 Reseat DIMM. 
2. 
 
 System board. 
The power-on password prompt appears. A power-on password or a supervisor 
password is set. Type the password and 
press Enter. 
The hard-disk...

LCD-related symptoms 
 
 Table 4. Minimum quantity of defective pixels required for LCD replacement on June 2006 
or later manufactured Lenovo 3000 
LCD resolution Bright dots Dark dots Bright and dark dots 
XGA, WXGA 5 6 6 
WXGA+, SXGA+, 
WSXGA+ 
5 8 10 
UXGA, WUXGA, 
QXGA 
5 13 13
   
Notes: 
v 
 
 Lenovo will not provide replacement if the LCD is within specification as we 
cannot guarantee that any replacement LCD will have zero pixel defects. 
v 
 
 A bright dot means a pixel is always on (white or...

Intermittent problems 
Intermittent system hang problems can be due to a variety of causes that have 
nothing to do with a hardware defect, such as cosmic radiation, electrostatic 
discharge, or software errors. FRU replacement should be considered only when a 
problem recurs. 
When analyzing an intermittent problem, do the following: 
1.   
 Run the diagnostic test for the system board in loop mode at least 10 times. 
2. 
 
 If no error is detected, do not replace any FRUs. 
3. 
 
 If any error is...

42 Lenovo 3000 N500 Hardware Maintenance Manual