Not booting after top case replacement?

So, I'm previously certified as an ACMT for an Apple self-servicing and would appreciate only others with likewise experience to respond to this question.

This machine was brought to me after having a run in with a glass of wine.

I was able to definitively conclude that the only damage to the machine was the power button had shorted out. I was able to jump it, get the machine to boot, confirmed all components and other keys were working, ran AHT, etc.

I went ahead with a top case replacement (without battery), opting to make an attempt to remove (and reuse) the battery with a heat gun (and some patience). Upon reassembling the machine, it wouldn't boot, post, chime, etc.

With the bottom case removed and everything exposed, I observed that the fans would kick on, but they'd just cycle on and off again.

I assumed I'd damaged the leads between the battery cells and ordered a "new" battery from an eBay vendor.

The item that arrived seemed to be a new part and came in the right packaging, but was marked with a serial number and had clearly been pulled out of another machine as the frame between the cells and the controller circuitry/connector was bent.

I installed the "new" battery and yielded the same results.

I disassembled the entire machine again, just to be sure I didn't miss anything when reassembling. Everything looks perfect, aside from the possibly defunct battery.

Anyone have any brilliant ideas or suggestions?

PS, this is the vendor the top case came from:

http://www.dvwarehouse.com/Apple-Parts-c...

They appear to sell brand new Apple Service parts to those who don't have access to GSX