Lenovo B305 Service Manual

Contents
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Contents
Chapter 1. About this manual ................................................1
Important Safety Information ...................................................................... 1
Important information about replacing RoHS compliant FRUs  ..2
Chapter 2. Safety information  ................................................4
General safety ........................................................................\
............................... 4
Electrical safety...

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Power Supply Problems ........................................................................\
........ 22
POST error codes  ........................................................................\
..................... 22
Undetermined problems  ........................................................................\
..... 24
Chapter 7. Locations ............................................................... 25
Locating components and connectors...

Chapter 1. About this manual
      1
About this manual
1
This manual contains service and reference information for Lenovo 
IdeaCentre B3 computers listed on the cover. It is intended only for trained 
servicers who are familiar with Lenovo computer products.
Before servicing a Lenovo product, be sure to read the Safety Information.
The description of the TV card in this manual is only used for the machines 
which have the TV card. It is invalid for those machines which do not have 
TV card.
Important...

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Important information about replacing RoHS compliant FRUs
RoHS, The Restriction of Hazardous Substances in Electrical and 
Electronic Equipment Directive (2002/95/EC) is a European Union 
legal requirement affecting the global electronics industry. RoHS 
requirements must be implemented on Lenovo products placed on the 
market after June 2006. Products on the market before June 2006 are 
not required to have RoHS compliant parts.
So, if the parts are not compliant...

Chapter 1. About this manual
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California Senate Bills 20, 50: 
• 
http://www.ciwmb.ca.gov/HHW/Events/AnnualConf/2004/
presentation/MPaparian.pdf 

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Safety information
2
This chapter contains the safety information that you need to be familiar 
with before servicing a computer.
General safety
Follow these rules to ensure general safety: Observe good housekeeping in the area of the machines during and 
• 
after maintenance. 
When lifting any heavy object: 
• 
1.  Ensure you can stand safely without slipping. 
2.  Distribute the weight of the object equally between your feet. 
3.  Use a slow lifting force. Never move...

Chapter 2. Safety information
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Wear safety glasses when you are: hammering, drilling soldering, 
• 
cutting wire, attaching springs, using solvents, or working in any other 
conditions that might be hazardous to your eyes. 
After service, reinstall all safety shields, guards, labels, and ground wires. 
• 
Replace any safety device that is worn or defective. 
Reinstall all covers correctly before returning the machine to the 
• 
customer.
Electrical safety
CAUTION:  
Electrical current from power,...

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If you need to work on a machine that has exposed electrical circuits, 
• 
observe the following precautions: –  Ensure that another person, familiar with the power-off controls, is 
near you.  
Remember: Another person must be there to switch off the power, if 
necessary.
–  Use only one hand when working with powered-on electrical 
equipment; keep the other hand in your pocket or behind your back.   
Remember: There must be a complete circuit to cause electrical...

Chapter 2. Safety information
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Safety inspection guide
The intent of this inspection guide is to assist you in identifying potentially 
unsafe conditions on these products. Each machine, as it was designed 
and built, had required safety items installed to protect users and service 
personnel from injury. This guide addresses only those items. However, 
good judgment should be used to identify potential safety hazards due to 
attachment of features or options not covered by this inspection guide....

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Handling electrostatic discharge-sensitive devices 
Any computer part containing transistors or integrated circuits (ICs) 
should be considered sensitive to electrostatic discharge (ESD). ESD 
damage can occur when there is a difference in charge between objects. 
Protect against ESD damage by equalizing the charge so that the machine, 
the part, the work mat, and the person handling the part are all at the 
same charge. 
Notes: 
1.  Use product-specific ESD procedures...