Hitachi LE55A6R powers on but no picture/backlight

[shelby5041]

this is a FYI post

i found a hitachi le55a6r in trash

plugged in and has red standy light...powered it on and blue power light comes on but no picture

flashlight test shows image there..so since this is a LCD LED tv i immediatley assumed it was a bad led light since this is very common in these tvs

took tv apart....removed lcd panel...found 1 dark colored led ..removed plastic led lens and ripped led light off the board to expose the pads...jumper soldered the 2 pads together as 1 and now tv works great

[budm]

Re: Hitachi LE55A6R powers on but no picture/backlight

Make sure to turn down the backlights level to as low as possible, also when you bypass the LED the PWM controlled MOSFET that maintain the constant current through the LED string will run hotter.

[shelby5041]

Re: Hitachi LE55A6R powers on but no picture/backlight

ok thank you

bypassing 1 led makes that much of a difference?

the tv has i think about 70-80 leds

[budm]

Re: Hitachi LE55A6R powers on but no picture/backlight

Each LED is about 1 Watts, so for the active device to maintain constant current, the Vdrops on the active device will increase when LED is bypassed, thus more power dissipation on the MOSFET.

[shelby5041]

Re: Hitachi LE55A6R powers on but no picture/backlight

thank you good to know

but the life span on these tvs are so short 1-3 yrs that nothing much really matters anymore lol

im sure the tv will fail in another way before that bypassed led would cause a failure lol

[shelby5041]

Re: Hitachi LE55A6R powers on but no picture/backlight

i got the tv for free so getting it to work period is most important...anything else im not worried about.....im just letting people know that this may be a common issue on this model tv so they can get their tv working again for no cost ....i could have repalced the LEd but i dont have one on hand and removing the led strip which is glued down could not go well so this was an easy way to get tv back up again with less risk of destroying tv even more..removing the led panel was not easy...i was very careful and it went well...

[shelby5041]

Re: Hitachi LE55A6R powers on but no picture/backlight

and these tvs are not worth putting more than $20 in them..since its only worth maybe $50 in working condition....the LED strips are too costly and not worth replacing...repalcing led itself is cheap but like i said i didnt have any..i ordered some last week for a diff tv but takes 30-50 days from china..