ELEMENT ELEFQ462 led/lcd power problem

[ilikesteel]

picked this up today cheap $40.00. allegedly was connected to house power and there was an electrical problem with the outlet, and the set wouldn't power on afterwards. she took it to a shop and they said power supply problem.
pictures will be forth coming! I did notice a broken diode in the power supply. a schematic would be nice to help troubleshoot. I was hesitant about this Element, however it's only2 years old and is a led/lcd. cannot find a service manual either! it has a samsung panel and at least one samsung board.

pictures coming!!!

thanks,

frank

[ilikesteel]

Re: ELEMENT ELEFQ462 led/lcd power problem

Pictures.

[budm]

Re: ELEMENT ELEFQ462 led/lcd power problem

Is the main AC fuse OK? Is it completely dead with no indicator lights? Which Diode? D4 as shown in the pictures?
More details on what you find as far as the voltage readings on the board.

[adriancel]

Re: ELEMENT ELEFQ462 led/lcd power problem

D4 seems to be 1N4007 and at that pin it seems to be a ferrite filter glued. Can you check that?
On the supply board there is F1 and F2 - fuses. Please check them for continuity.
Please check on the back of the power supply board for blown components.
Do you have and know how to use a multimeter?

[ilikesteel]

Re: ELEMENT ELEFQ462 led/lcd power problem

budm and co,

yes I can use a meter.

full pic of the back of the TV.

voltages, here goes. when you plug the pwr cord into the ac outlet. a tiny red led flashes on the upper right long samsung board.

on PS, I thought D4 was bad because it looked like it broke, but that's not the case. it may be glue as stated. I measured 118V dc across that device.

with cord plugged in, no power switch. I get 24v on the upper PS connector on all 4 red wires(4 red 4 blk) on that connector.

front of TV has a red led on solid where the element logo is at the bottom of the front of the frame.

on the lower PS connector I get 12v on the two yellow wires, then 3 gnd blk wires are next in line. skip two pin spaces, then 5.2v on purple wire, 5.0v on green wire and 5.2v on the next two red wires.

when I press power switch, blue led's light on the soft key panel for power, channel, volume, etc. they stay on for 3-5 seconds, then go off. red led on fron is always solid red.

press power again and same cycle repeats.

I cannot see a voltage pin out label from the top of the board.

strange to have all the voltages with power plugged in and also when power switch is pressed. help

thanks

frank

[adriancel]

Re: ELEMENT ELEFQ462 led/lcd power problem

When you switch on, the backlight is turning on?
it no, try to unplug the cable that feeds the inverter board and post results.
Also check F101.

[ilikesteel]

Re: ELEMENT ELEFQ462 led/lcd power problem

When you switch on, the backlight is turning on?

NO.

it no, try to unplug the cable that feeds the inverter board and post results.
Also check F101.

this tv doesn't look like a reg lcd TV. which is the inverter board on this TV please?

check F101 on the main PS?

thanks very much,

frank

[ilikesteel]

Re: ELEMENT ELEFQ462 led/lcd power problem

ok, F101 on the inverter checks good, 0 ohms across the fuse.

unplugged PS to inverter connector. I don't see the back lights coming on when plugged in and hitting the power switch.

same cycle of events, all blue panel lights light up for 2-5 seconds then go out.

red led on front steady red.

thanks so much guys,

frank

[ilikesteel]

Re: ELEMENT ELEFQ462 led/lcd power problem

more info:

everything connected, power plug in the ac outlet, not pressing power on switch.

power supply readings.


Conn-1 conn-2
Pin 1- Gnd nc pins 1-4 red 24.3
Pin2- gnd nc pins 5-8 blk gnds
Pin3- red 5.2v
Pin4-red 5.2
Pin 5-grn 5.0 pson goes to main board
Pin 6-purple 5.2 5vsb goes to main board
Pin 7-nc 5.0
Pin 8-nc 5.0
Pins 9,10,11 blk gnds
Pin 12 -yel -12.0
Pin 13-yel- 12.0

help.

thanks frank

[budm]

Re: ELEMENT ELEFQ462 led/lcd power problem

This is a LED backligts TV, it does not use high voltage inverter board for driving the CCFL.
Are there any labeling by the connector on that long board (with two black square transformers) in the middle of the chassis?

[ilikesteel]

Re: ELEMENT ELEFQ462 led/lcd power problem

budm,

yes, there is a white label "02867ATB0303059C2". bottom of board is a white stenciled label on the board, "SSL460EL02 Rev 0.2. and the name Samsung stenciled in white.
from top of board is a cable coming from the top of the panel with 8 wires.
wires are blk wh, blk bl, blk wh blk bl into CN201.

CN101 goes to power supply board, has 4 red 24.3 volts, 4 blk gnds, same connector also has three wires connected to main board, red, grn and a blk and all 3 have .001 V.

isn't it strange that I have all the voltages from the PS board with power connected to the TV without pressing the power button?

main board has a white label "1104H0548-h" and a stenciled CV318H in white.

when power is pressed, front soft key panel at bottom of set lights in blue for each switch, source, ch up/dn vol up/dn, pwr and menu. the power blue led blinks 2-6 seconds when pressed and then all panel lights go out.

red led in front bottom is always solid red, no blinking.

no light on screen, no sound , no image. cannot find schematics or service manual. set is only 2 years old, may 2011. did I find a dud to repair?

thanks for comments budm. just point me in the right direct to help isolate the problem.

thanks very much,

frank

[budm]

Re: ELEMENT ELEFQ462 led/lcd power problem

The CN102 has some kind of printing close to it that I cannot read from the picture. It seems to me right now that it is not getting the BL_ON signal to turn on that board. Are there any DC voltages on those 4 large caps?
I believe that TWO of the 3 wires is for BL_ON, Dimming.

[ilikesteel]

Re: ELEMENT ELEFQ462 led/lcd power problem

budm

I will check all that in the AM. 1:30am here in NJ.

thanks

frank

[ilikesteel]

Re: ELEMENT ELEFQ462 led/lcd power problem

budm,

more pics of the inverter and the main board. inverter has no printing on the bottom side of the board.

on PS, 4 big caps, all read +389V.

the 3 wires from main board on J1 (labeled as inverter) go to cn101 of the inverter board. it's a 6 wire connector with only 3 wires connected.

1st 2 wiring positions and last pin have no connections to them. underside of board indicates 12V on both 1st 2 pins. (picture 100_782)

the next three pins are labeled on the underside of board as on/off, purple wire to cn101 1st pin, adj, is green wire going to cn101 pin 2, and blk wire is a gnd going to cn101 pin 4 with other blk wires.

this is my numbering order because I cannot find any labels indicating the real numbering sequence of the connectors.

thanks a bunch budm and company!

frank

[budm]

Re: ELEMENT ELEFQ462 led/lcd power problem

"the next three pins are labeled on the underside of board as on/off, purple wire to cn101 1st pin, adj, is green wire going to cn101 pin 2, and blk wire is a gnd going to cn101 pin 4 with other blk wires." OK, that ON/OFF is the backlights on/off control, the ADJ is for the backlights dimming control.
The ON/OFF should toggle high when you turn on the TV, if it does not change state when you trun the TV ON and OFF, then the main board is not sending the control signal.
By the way, did you check the DC voltage on those 4 large caps on that LED backlight (inveter) power supply?

[ilikesteel]

Re: ELEMENT ELEFQ462 led/lcd power problem

budm,

are the 4 capacitors you wnated me to check the two long black caps and the two shorter yellow caps on the inverter board where there are two large transformers? I did not check them, but if those are the 4 you're interested in, I'll check them and report back.

all 4 large long caps on the main supply were 389V across the plus and minus leads of each cap. I will also check for signal change at the on/off wire on the main board.

how does this led/lcd combo actually work. the main backlights are ccfl lamps and part of the backlighting are led's? trying to understand how and why.

is that why there is no sound or image being displayed, because the backlight circuit must come on before an image or sound is allowed to be presented?

thanks very much, will report back.

frank

[budm]

Re: ELEMENT ELEFQ462 led/lcd power problem

Yes, those are the caps (laying side way).
This TV does not use CCFL for lights, it uses LEDs for backlights.
LEDs (or CCFL) are just for light source. The panel is still LCD same as always.
If the main board is not sending the signals to the backlights power supply board, then there are problem on the main board which that is why other functions do not work either.

[tom66]

Re: ELEMENT ELEFQ462 led/lcd power problem

The backlight is fully LED lit. There are no fluorescent bulbs. The LCD is the same in a conventional "LCD TV" but the LCM (liquid crystal module) has LEDs instead of CCFL tubes for backlighting.

The 389V powers four strings of around 120 white LEDs (120 x 3.2V/LED... it may vary depending on the LEDs used but it will be around 100 to 150 LEDs.) The four strings are in parallel. Because the strings are not perfectly matched, the current may vary between them. The four big heatsinked transistors on the board are responsible for dropping the final few volts and regulating the current, making sure each channel has the same current flowing through them. They usually also provide the pulse-width dimming (http://en.wikipedia.org/wiki/Pulse-width_modulation). So effectively you have 480 LEDs of equal brightness, likely in four separate strips, two in the top and two in the bottom. Assuming an LED power figure of 100W (the exact figure will probably vary), that gives 65mA per LED, which seems reasonable.

[ilikesteel]

Re: ELEMENT ELEFQ462 led/lcd power problem

Tom66-budm,

thanks for you comments.

ok, all boards reconnected, cables secured. power cable plugged into outlet.

on the main PS all 4 caps are 33uf, 450V rating.

all read +389V.

all voltages seem to be present +12, +24, +5, didn't see a label for 3.3v.

on the inverter board, two black long caps 47uf, 450v rating, both have 24V across plus and minus leads.

opposite side of board two yellow shorter caps 680uf, 35V rating, they both have 24V across plus and minus leads.

one other small yellow cap middle of board is 220uf, 35V rating and it reads 7.1V

monitoring the on/off signal at the mainboard before hitting the power switch, it reads .009V.

when hitting power switch, there is no change in the reading of .009V.
did it multiple times, the power switch blue led blinks on the soft panel, no change in output.

many thanks to everyone. is there hope for this one? I haven't seen to many element TV's on the forum.

frank

[tom66]

Re: ELEMENT ELEFQ462 led/lcd power problem

What voltage do you see on these test points? (The gold/copper pads.) I'm expecting less than about 20V per pad.