Exactly

Nope, LEDs are usually driven by current stabiliser. So shortcuting one diode should never mind for short time. BUT the tweezer with glue tape is something extraordinary dangerous. Do you know that this is a work under voltage that ONLY professionals are allowed to do?!? Has this tape certified insulation for 230V? Using multimeter without main power source is without any danger. Also it is a nonsense to use knife instead of soldering device :(.

This guy is gonna get someone killed. It's not even worth the effort. These bulbs are less than $2 USD now. Any yes. The more LEDs you remove from a designed circuit, the harder the remaining LEDs are driven. This is a fool's errand.

@@dzdg6mmdzdg6mm You are wrong, these are cheap devices and rely on the correct supply voltage to limit the current. You are correct that leds are current operated devices and a typical led requires about 3 volts dc to ensure the correct current. 12v across 4 leds connected in series, which these plainly are, allows the correct current to flow. Shorting one out puts 4v across each of the remaining leds and increases the current through them resulting in premature failure. There is no current limiting circuitry built in that would allow you to short circuit one led and keep the current constant. This would mean a pointless increase in manufacturing costs. You can easily find circuit diagrams of this type of lamp on line which will tell you everything in more detail. Since writing this I have been thinking. There is a 1 m ohm resistor in the mains supply to the rectifier. This means that if you short circuited all the LEDs the current flow would still only be 24mA. Maybe it would work.

@@dzdg6mmdzdg6mm The LEDs operate at low voltage DC. Probably about 5 volts, 12 volts MAX and obviously low current. The part he is working on is all DC. Think about it. If it is a 10W bulb how much voltage and current is that?