soldering computer motherboards

yes with the right equipment you can test a motherboard however unless the chip is in a socket that you can unplug and plug it back in I would not recomend it. The test equipment is expensive. buying a new motherboard is cheeper than having it repaired. The tech that can repair/solder a mother borad is going to end up charging more than the motherboard is worth. Thus the recomendation for replacing them.

The chances that a damaged motherboard can be repair are very low and mostly it would worsen than solving the problem. However small problems can be repaired as long as we don't resort to using soldering iron.

If you are really interested in learning motherboard service, refer your local yellow pages, "computers- repairs/ service" and contact people with word "chip-level servicing". These business takes new candidates and train them as on-the-job training at certain cost. Also, you can refer academic section, and look for "electrical and electronics institutes".