The reasons of single color high power LED lamp bead burning are as follows
01. The two upper and lower filaments are called gold wires in our industry. Pure gold is used for conducting electricity. There are two positive electrodes and two negative electrodes. A really good product will have a fifth wire, which is welded on the zener tube to protect it.
02. When the filament becomes shorter, it has clearly told you that your lamp has been burned by high current, which is equivalent to an open circuit.
03. The driving current of single color high-power LED lamp bead 1W is about 350mA, and the working voltage is between 3.2-3.6v. Please pay attention when using, too much current will burn the lamp.
04. Generally, the aluminum base plate of three 1W lamps is driven by 12V or so. Few of them are directly driven by 220V. Do you think there is a constant current source or a 12V driving power supply missing?