how to repair motherboard
Generally you won't find schematics. You should know the block diagram of a particular chipset you need to test, the important signals, a scope and lots of experience and common sense in electronic repairs. Here you can get some schematics for some laptops: **broken link removed** .The forum is in vietnamese. use a transloator like google or yahoo's babelfish and registr on the forum and download the schematics you need.
The problem for someone with a degree is that they think that without a schematic they can't troubleshoot anything. Start experimenting on dead motherboards. Take your time to lean what is worng in them and try and fix them. Use sites like
www.alldatasheet.com and similar sites for datasheets on particular components you need. For dead boards, you need to see if the clock is present, check if the PWM IC is giving all its outputs, Check the VRM ICs and the MOSFETs. And ofcourse leaky electrolytic caps are a big cause of boards malfunctioning. Ideally an ESR meter can help you in locating bad caps in circuit.
Use any and all experience in reapiring any electronic devices.
For a microprocessor. it needs power, clock, address and data to function. Keep this in mind. for boards, you can check the signals in the PCI slot. A debug card can help in troubleshooting. Look for chipset block diagrams, learn the functions of the processor pins. learn how the power on and reset circuitry of INtel and AMD processors and chipsets functions. If you master any intel processor board right from 486 or pentium 1 onwards, the new chipsets are only modifications of the old processors. Some signal names change, but the basic functions are the same. The same applies to AMD or VIA chipsets.
Troubleshooting a circuit is a way of thinking. It can't always be learnt from books. You have to keep trying at first. It take a long time initially, but once you have done around 20-30 borads you'll have some confidence in repairs. Another way is to come to India and learn in a month or two how they repair boards. Some insitiutes are actually repair workshops who also teach repairs. Don't be fooled by appearances. Some of them wont bother about static prevention as in tropical areas with high humidity, static buildup is minimal.
Old hard disks, CD/DVD ROM drives sometimes yield good SMD components.
In India, Thailand, Hong Kong and other Asian countries, there are many who repair motherboards successfully. We even replace chipsets and GPU ICs. Of course for that you need an infra red BGA rework system.
Start thinking outside the box and start repairing.
Best regards!