Although photos of solder can be mis-leading, it appears to me that the solder is very poorly placed on R17 (near the 7 of R17 text). You can take a soldering iron, heat it up. Wipe the iron across a fairly damp sponge several times to clean the tip, wait 5 to 10 seconds for the iron to get back to temperature, and touch the iron to that resistor edge AND the little pool of solder next to it at the same time). In just 2 to 4 seconds, you should see the solder flow up the side of the resistor and then remove the iron. Don't heat too long, if nothing happens in 5 seconds, repeat but at a little solder as you heat.
before you start, you can take some more photos at a better angle to confirm for yourself that the solder is not well placed.