Palsonic backlights

[loopyloo]

I'm looking at a 50" Palsonic LCD TV.
Everything works except the backlights. but I can see white light flash briefly through one of the back cover holes at power up
)
I found 1 swollen cap on the psupply and replaced it but the fault was still there so I stripped the tele to get at the leds.

The backlight consists of 5 strings of 14 leds, each string with their own connector. The strings appear to be connected in series at the PSupply. I found 3 burnt leds but am now confused. The leds have their own little copper pads either side that connect directly to the led for testing but I can't seem to get any measurement from any of the leds and applying up to 4volts across any single led does nothing. Surely they can't all be blown ???

What do you think ?

[loopyloo]

Took a punt and raised the test voltage. They work individually at 5.5v somewhat dim and bright at 6
I have led strings from another tv but they are bright at 3volts.
Do some tvs use leds with built in resistors ?

[Tom Mix]

Never found resistors in any led I used from tv backlights, they are in series strings. These LEDs removed make. the best torchwith resistor to give 100mA current each with reflecter.

[Tom Mix]

Dim memory faltered inseries string, 1 out all outas in Xmas lightscan bypase/s ledes or graft in replacement/s caution over 100v driving strings.

[loopyloo]

Now I realize why the difference in led voltages.
The leds in this palsonic are twin led (2 elements in one).
I can't see how I'll ever match em up so might have to dump it.