Chosen Solution

Hello, I have what I believe is a Non-Water damaged Mid 2009 MacBook Pro that I recently picked up from eBay. However when I tried to turn it on, I found something I have seen happen before, which is that the MacBook does not respond to the keyboard at all. So I took off the bottom panel and shorted the power button pins, because that always works for non responsive keyboards, however not only did I find zero damage on the cable or anything else, but shorting the power button pins yielded no response at all. No fanspin, no power to the hdd, no DVD drive noises, just complete silence like the battery was dead or something. I have tried resetting SMC, but that hasn’t worked because the MacBook does not respond to any activity on the keyboard. All it does is charge the battery and display how much percentage is left from the built-in battery meter. Any help is appreciated as I’m at a loss as to what is going wrong here. I also do have a hot-air station, so if there’s any keyboard controller chip that goes bad, I can replace it.

Unfortunately after thoroughly examining and diagnosing the board and finding absolutely nothing that looked wrong or was shorting at all, I have decided that the best course of action is to buy the best compatible motherboard for it (a 3.06ghz T9900 motherboard to be specific). After disassembling it I figured out I actually had been scammed by the seller as well, as the CPU was a 2.66ghz CPU, and not the 2.8ghz CPU that was advertised, not like it mattered though, as the board was completely dead for some unknown reason. I should also mention that I bought this computer as-is specifically to repair, too, so it’s not like the seller was going to accept returns. Anyways, I want to thank everyone that tried to help in this situation, I really, really appreciate it.

Frankly I’s return this one to the seller.

What is the onboard battery checker telling you? Do you have four or more LED’s lit? If you do then the issue is within the logic board, at this point you’ll either need to debug the logic board circuits to see if you can fix it or just replace it. At that point I agree with @mayer this will likely cost a bit of change ($60 ~90 for a used logic board if you can find one) to get the working again. I think you should return it to find a better system.