I recently purchased a MacBook A1278 late 2008 from eBay with the intention of repairing it, and after buying a replacement for the missing DC-in board the laptop still does not boot and the light does not turn on on the charger. The laptop had clearly been tampered with in the past (some screws and non-essential brackets were missing, there were signs of heat on the DC-in plastic connector, etc.) and I have identified what I think is the culprit component on the board, on the flipside of where the DC-in connector is (see pictures). It looks as though someone has attempted to (re?)solder this chip to the board but has succeeded in bridging (or possibly breaking, it's difficult to tell) all of the connections on one side.
I'm suspecting that this is shorting and causing problems, since when the charger and the battery connectors are plugged into the board the battery terminals in the case pop up to about 0.6 volts every couple of seconds before dropping back to zero, which could be the charger auto-limiting the current because of the shorting component.
Under the assumption that this chip is actually meant to be on the board and isn't some shady replacement or add-on, what does it actually do? The board is devoid of labels (thanks, Apple) and so the only information I can provide is that the chip is directly on the opposite face of the board to the small white fuse/transistor sitting next to the DC-in port, is about 5mm by 4mm in size and has 1127662 printed faintly on the top. Is it possible to get replacements for these chips if it turns out this one is totally borked?