I had stopped repairing PC motherboard since i left my former computer distributor company back in 1994. Those days the famous motherboard board were the 486sx, 486dx and the Pentium. I was provided with every model of the motherboard schematic diagrams, Chipset (all range of IC’s), SMD desoldering tools, troubleshooting notes and even the POST diagnostic card. Repairing PC motherboards on those days were quite easy but i doubt nowadays it will be easy unless you are working in the motherboard manufacturers or you have the sources for all kind information related to motherboard.
Occasionally i do have motherboard sent for repair by my friend who deal with selling computer systems. Most of the time was the electrolytic capacitors bulged and quite simple to fix it. Nowadays PC motherboard is quite cheap and less people want to repair it and prefer to buy a new board unless if the motherboard is in the higher range (branded). As mentioned, if you can’t source for the parts it would be very difficult to repair the board. Those days the boards were only using normal SMD IC’s (spider IC’s) but most of the motherboard now are using the BGA IC’s which is very difficult to extract unless you have the special equipment to do the job.
It will be very time consuming to do this precision job unless the profit that you gonna make could cover your cost otherwise it would not be economical to repair the motherboard. If any of the readers in my blog repair motherboard i would like to listen to what you have to say about motherboard repairing business-thanks