Why does this circuit blow up LEDs?

[Mooly]

I can't kill the LEDs anymore. It's just the line straight one that behaves in this strange way. It just flashes briefly when it's supposed to stay lit. And again, only if another LED is already on - otherwise it remains completely dark.

I've looked over the connections and everything seems completely perfect, and even if I just semi-press the switches (trying to cause an intermittent connection), nothing bad happens.

It literally works perfectly now. Minus that weird line straight...

This LED connects directly across the LED supply when active. You need to measure the voltages around the circuit logically. Get the unit in the fault state and connect the meter negative to the LED negative supply at the power supply itself. Then turn the direct switch on and measure working your way up to the direct LED. Was the cap discharged when you fitted the LED's ? Maybe you have still inadvertently damaged this LED. Voltage checks will reveal the problem.

 

[mandu]

LED blowout

This is a current limited (series resistor) LED circuit. You can blow LED only by applying reverse voltage. Check where the reverse voltage is coming from.
Regards,
mandu

 

[Mooly]

This is a current limited (series resistor) LED circuit. You can blow LED only by applying reverse voltage. Check where the reverse voltage is coming from.
Regards,
mandu

Not on this one 🙂 A momentary break in connectivity can zap the LED's. Look at the circuit of the PSU feeding them.

 

[mandu]

LEDs can handle 3-4 times inrush to their rated current for a short time. If the capacitor discharge could be the problem, Then adding a small resistor (about 470 ohms) in series after the capacitor for the LED circuit should solve the problem at a slight reduction of brightness.

Regards,
mandu