Replaced LED twice, keeps popping almost immediately.

[skoglor]

Hi all, I'm working on a Hisense 50H6E that blew a LED. Knowing nothing except how to solder on a new LED we ordered from amazon a package of:
"SMD 0.5W 2835 LED"
v(f): 3v - 3.2v
i(F): 150mA

These LEDs looked like the same size, so i went for it and it worked for about 5-10 seconds, got the tv splash screen and then it bzzt the picture went out.

Did I just order the wrong junk SMD LED? Reading up around here I see there are definitely different types of LEDs, and ratings.

EDIT: just now looking at the power board again I see 160v/400mA in the output specs. Is this my backlight voltages and led spec? so 160/36 total LEDs=4.4v? should I look for 4.4v 400mA LEDs?

Or should I be looking at the power board?

Should I solder on another, and get a reading from the LED output on the powersupply board before it fizzles out again?

Thanks from Idaho!

[budm]

Re: Replaced LED twice, keeps popping almost immediately.

You need at least 3V 1W LED. The LED string is not exposed to the full Voltage of the power supply, part of the power supply Voltage will be on the PWM controlled MOSFET and current sensing resistor for maintaining the constant current through the LED string.

[dick_barton]

Re: Replaced LED twice, keeps popping almost immediately.

Your led must be capable of handling 400mA and would is most likely a 3V led.

[petehall347]

Re: Replaced LED twice, keeps popping almost immediately.

check vf of an original good one

[Diah]

Re: Replaced LED twice, keeps popping almost immediately.

1- measure yours Old burned LED again.. the label of the set tell they are 3030.
2- not all LEDs what you buy are designed for TV Backlight however the seller write they are.... check the LED you bought and measure them with DM on Diode mode.. it should read diode ( Ziner FV ) on side and when you reverse the probe it should light on at any level notice bar of light.