Not turning on, possible shortened circuit.

I replaced the CMOS battery an forgot to plug in the fan plug. After i fixed that it worked for about 20 min and i gave it back to my friend. About 1 hour later it came back and he said it just shut off after about 45 min. I tried to power it up but no lites,on batt and plug power. When i took it apart again i looked at where the main power adapter plug attaches and there are like 3 strips of solder on the back that look like it is pitted /black not sliver looking. Would this prevent it from power on by just the battery also? If this is the problem what is the name of the whole plug board that is not part of the rest of the motherboard and can i fix it?