Re: Samsung UN32F5500 with bad LEDs

Yes, I confirmed using zener diodes for every busted leds (1:1) in reverse bias, instead of, using 1N4007 silicon diodes. I used a simulation software livewire and it did work well. Nice!!!

Note: Just use 1 Watt zener if constant current supply is below 300mA; 10 Watts for more than 300mA

Re: LG 60pz550 sound but no picture

First, check all the cables if they are inserted properly. Check module pattern by using 'Tilt' key on SVC R/C. Proceed with the instructions of Hamie. Check and adjust Va and Vs voltage (refer to module label/sticker for the Va and Vs values). If normal, then, check voltage -Vy, Vsc, VzB, if not, it's a power problem. If -Vy, Vsc, VzB is normal, check B+ voltage on power board/control board, check B+(5V), if not normal, check Y-Sus and Z-Suz Board and replace defective B/D.

Re: Samsung UN32F5500 with bad LEDs

I wonder if I can use a piece of 3v or 3v3 zener diode for every busted LED with voltage rating of 3-3.3v at a constant current supply of 200-500mA by the LED driver. What do you think?

Re: Samsung UN32F5500 with bad LEDs

Oh, yes, I agree the Vf is not 1V when If is 200-300 mA (high ampere) but 0.80-0.83V from the graph. Thank you.

Re: Samsung UN32F5500 with bad LEDs

Resistors can be a good way to lower the current, but, if you are using high power LEDs with a few hundreds of mA, that will be tougher to drive. I suggest you use a switching current regulator instead.

Re: Samsung UN32F5500 with bad LEDs

Four (4) IN4007 diodes in series would be enough instead of 5, if you plan to have a 3.5v drop for every busted LED. Four diodes in series would be equal to 4 volts because each diode consumes 1 volt as forward voltage, so, 4 x 1 volt =5 volts. However, to be safer, if you don't know the exact voltage requirement of each LED, I suggest that you use 6 IN4007 LEDs = 6 volts for every busted LED for any brand of TVs. A TV backlight is usually rated at 3-6 volts. The current will have a maximum of 1000mA or 1A for a series of diodes (regulated), since,...