Flashing LED board quit working

[Hereforthealibi]

This is a lamp made to look like a railroad crossing sign with the two alternating flashing red lights. Each light in this lamp are comprised of 6 LEDs on a circular board with F-D6016 printed on the back. Piggybacking on that is another small rectangular board with JH-107 printed on it. (Pics attached). There is a black dot/bump of some sort of material on the smaller board in the middle of the circuits - not sure what this is.. This board holds a resistor as well as manages the power distro to all the LEDs. All the connections are still intact. The other “lamp” still flashes normally. This one does not flash or light up at all.

Does anyone have suggestions on troubleshooting steps or rationale for why this one side quit working?

 

[bidrohini]

Check with a multimeter. Find out if there is a broken trace somewhere.