I know first, I would like to see a picture of the board. Do you have power and ground on the U16? Make sure you are testing on the legs of the part, especially if you have it in an IC socket.

The battery corrosion may eat into the trace and sever it right at the pin pad and may not even notice it, especially if you already lightly sanded the trace to expose the copper.

Need to be sure you remove all the black areas of the battery corrosion from the board, or it will still continue to spread like cancer and continue to eat up traces and parts. An example of one I had repaired.20170408_115512 (resized).jpg20170421_185553 (resized).jpg

You definitely have some more work to do. Pretty much can follow the corrosion from the bottom left and right battery pack holder holes and see the damage from there that spread up the traces and also and fumes that got to the resistor leads that are marked off. Picture does not have good light on it, so there could be some another area that I can't see affected. Could even use other pictures from other angles. Hard to really tell if L1 and C32 were affected. Some of the resistors I marked off on the right may not be damaged, just might be the way the light hit the area.

Basically, if the solder joint and solder leads are not shiny, need to suspect it for having battery corrosion. Magnifying glass is your friend for closer examination.
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I always replace the parts there were hit. I remove the damage parts, sand the affected areas down to the copper, treat the areas with vinegar, clean the board with alcohol, fix any damaged traces, reclean with alcohol, and repopulate with new parts and coat the bare copper areas.

My opinion, I can not see how the Zep is supposed to clean inside the parts that were affected. Sure it may look like it from the outside of the part, but you can't exactly scrub inside a part, much less under a part if the part is mounted tightly to the board.

https://pinside.com/pinball/forum/topic/terrybs-guide-to-repairing-alkaline-battery-damage

If you use the Zep instead, still make sure you are replacing the damaged parts. I definately would remove that IC16 socket just so I can get underneath and clean the board under it.