Wireless charging not working after battery replacement and new board.

What do u mean by wireless charging board there is no seperate wireless charging board on the s7 the main phone board handles charging and the pickup coil for the wireless is a thin flexible piece that goes at the back it connects to the phone through small copper spring like contacts that make contact when it's all put together.

I dont think this guide is quite complete but this is the part that picks up the wireless charging the guide isn't really showing u properly where it makes contact from what I could see but u can flip the coil over and have a look

Samsung Galaxy S7 NFC Antenna and Charging Coil Assembly Replacement

Also look at the following especially step 7 and 8 u can see the coil and the gold colour contacts for the coil on the right in step 8 image Samsung Galaxy S7 Teardown

I have the exact same issue that you had. I got my phone as a refurbished unit from Sprint. They told me it had a new battery. It didn’t. They told me all the features will work. They don’t. I can’t say that the wireless charging has ever worked on this phone. I used to have a thick case on it and I assumed that the case would not allow the charging, but even without a case, it still won’t charge. I replaced the charging coil today with the iFixit part (which fit perfectly!) but it still won’t charge, so there is something else wrong.

This phone has Android 8.0 on it and does not show any settings that I can find for turning on wireless charging like the older versions do.

The answer that c9679 gave you is of no help whatsoever, so I’m not sure what to do. If someone knows of a setting to turn this feature on and where it’s located, that would help immensely.