What's the cause of the noise during the aging of LED bulb bulbs?
This should be the power problem. It's easy to make a noise because there are so many parts of the power supply.
The power supply LED bulb using miniature low power switching power supply, switching transformer due to loose, and the switching frequency did not avoid the audio area, it will beep.
The sound may be come from the power supply module components aging or faulty soldering and desoldering. LED long life, but may also be some problems.
Either AC or DC LED lighting there will be a power module, a small hidden in the lamp body, the daily working state can produce high temperature, if the AC power supply temperature will be higher, because the lamp body appears to flicker, high temperature and long time will lead to the power supply module parts welding, weld or aging, so a lot of alternating current LED lighting the metal shell, to facilitate heat dissipation, the DC power supply is adopted to eliminate the flicker, reduces the electrical power, so the DC temperature should be low.
