If you compare the under-side of the PCB with the bulb's case, you'll see if the thermal pad was adhered properly.

In these photos you can see the pad was only partially attached on one side. The other side of the PCB was lifted several millimeters away from the bulb's base.

The bulb's metal base serves as a heatsink. You can see the air channels running vertically along the sides. This is why these bulbs should only be installed in a vertical orientation to maintain proper airflow.

If you plan to re-assemble the bulb, you should scrape off all the old thermal pad from the PCB and case. Both surfaces should be clean. Replace it with a good thermal adhesive epoxy, following the manufacturer's directions.

Note the two Phillips-head screws in the central portion of the metal case (marked in green circles). We remove these in the next steps.