Seiki SE322FS lcd tv powers on fine but no backlight

[shelby5041]

hi

i have another small project tv....tv was made in 2012

its real cheap and cheap made led lcd tv so so investing more than a few bucks wont be economically smart

anyways....its so cheap it has 4 boards built into 1

power supply...inverter ....main and tcon all on one board

all caps look fine...

i have seen on shop jimmy something about eeprom ..that repairs a list of common issues with this tv....including backlight not on issue

anyone have any experience ...it seems to be a very common issue with this model tv

[shelby5041]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

well my first search came up empty on here and 2nd search for some reason i see tons of seiki tvs with no backlight threads so i will look....in the meantime if someone has any input please go ahead

thanks

[whiz62]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

I had picked up a Seiki SE32fy22 and it had no backlight but could see the no signal on screen with light. Took it down to the leds and one connector was not fully seated. Be very careful with panel going back together if you try this. I chipped the corner of panel and ruined it. So now I have almost new tv with no Lcd panel. Live and learn.

[CapLeaker]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

measure the voltage on the backlight. Tell us exactly what is going on. My guess is a burnt out LED.

[shelby5041]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

i will check voltages today later on....that may guide me better......i assume these are designed like the old xmas lights.....if one led burns out ......all the led lose power?.....wait a minute.....u saod burned out led....i thought leds last forever?????

[shelby5041]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

i have torn apart many lcd tvs and many lcd monitors.....ill b careful........i make lights out of broken screen lcd monitors.....have 3 on my work bench at work......and i used 3 led strips from a broken tv under my shrlf on bench...theyvr very bright.......i love recycling

[budm]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

https://www.badcaps.net/forum/search...archid=4995547

[shelby5041]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

update..i do have 60v going to led lamps....

[shelby5041]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

update....disconnected 1 strip led jumped it out.....now bl comes on minus 1 strip.......looked like suspect bad led on that strip.....

now what?

[shelby5041]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

can i jump out 1 led on strip?

[shelby5041]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

or can i wire in a led strip from a diff tv.....i have some....or are there diff voltage led strips?......or all require same voltage.....that they put in tvs

[CapLeaker]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

You can either replace the LED with a new one or you can put in a zener diode into the LED's place to "fool" the PSU into thinking all LED's are there.

[shelby5041]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

thanks.....replacement to costly....and not sure how to do the zener diode....so i jusy removed bad strip and repositioned the remaining 2 good strips and its bright enough...with 2....pic is fine.....

tv fixed.....

never would have thought bad led.....suppose to last forever.....figured it was ps issue .....its a cheap tv so i will leave as is...it works good......thanks capleaker and others.....when i tested good voltage going to backlight i guess issue was backlight by default

[shelby5041]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

dont want to risk taking apart again...lcd very fragile.......ill stop while i got a good working tv now......just a tad dimmer but not really noticable.....

[budm]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

BTW, you can use 5 1N4007 connected in series to simulate the white LED.
https://www.badcaps.net/forum/showthread.php?t=46403

[CapLeaker]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

glad you got her going!

[shelby5041]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

yeah....thanks...ill pass on trying to repair the defective led....its not worth the hassle ..and the more i mess in thrre the more chances ill damage the lcd accidentally.the picture is fine withoit the 1 strip.......i repositioned the remaining two to maximize brightness evenly.....

[shelby5041]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

here are pics of how display looks when i removed i led strip and respositioned other 2....

not tooo bad

it is a little darker in center where there is no led....but its not bad

looks worse in the photos then in real life due to how camera takes pics

[shelby5041]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

one question i have is why is it that when one single led goes bad it causes all the leds to not power on......with todays technology that should not happen...........its like the old day on a string of xmas lights when one goes bad the whole 250 ct string goes off and u have to hunt for the bad one and replace it.....this is outdated technology

why????

[budm]

Re: Seiki SE322FS lcd tv powers on fine but no backlight

They do the series string because it is cheaper, to drive each string (I.E. 4 OR MORE STRINGS) then you need more circuits, but if one string is bad the protection circuit will kick in, it is not much difference than the CCFL, one lamp is bad then whole circuit is also shut down.