haier le42b1380 power supply issue

[budm]

Re: haier le42b1380 power supply issue

Two strings are in series as shown in the pictures that I marked, so when you remove the connectors, you will only see the Voltage on the Anode of the string that is connected to the Cathode of the Diode, the second connector that is in series withe first string will not show any Voltage on the Anode pin since if the LED string are not connected.
https://www.badcaps.net/forum/attach...7&d=1416623866

[budm]

Re: haier le42b1380 power supply issue

OK, I just check the function of my board, since there are two separate circuits for each set of the LED strings, I am able to remove on string of the pair (two strings connected in series), the other pair will stay lit.
It looks like one pair is for LED top half left and half bottom left, the other pair is for top right and bottom right.
The Voltage at the Catode of the Diode is 40VDC with LEDs connected, 45V without LEDs connected which means it does not have open circuit detection, I can see that it does not need the shut down since it has two LED strings connected in series and that is, if one goes open circuit nothing will be damage since the open circuit Voltage is only 45V and no multiple strings (more than one set of LED string connected to the power supply) nothing will be damaged. I probably does have over current protection if the LEDs shorted out.

[budm]

Re: haier le42b1380 power supply issue

Double post.

[freakaftr8]

Re: haier le42b1380 power supply issue

so if the supply is immediately shutting down the LED power including the 12 volts to the mainboard this doesn't necessarily mean an imbalance of the LED strings that if you can detach 1 set and still power the other.. interesting.
I have tried disconnecting the main board and powering the supply through jumpering the on off with the 5 volts and it just does a quick Blip voltage again so obviously I have eliminated the main board from being an issue

[budm]

Re: haier le42b1380 power supply issue

OK, it finally went into shutdown, one of the string has resistance to the chassis when I tested it (remove the connector from the board).
I turn the TV back on with just one pair of the LED strings connected and it comes on, then I plug that connector of shorted string (bottom left) to the chassis, I can hear big spark when I insert the connector then the TV went into shut down.
So right now I am just running with one set of LED only and it is still running with top left LED string and bottom right LED string connected to one power output.
I am not going to take the screen apart until the other string go out since I do not believe it is good design and more likely the other string will go out later.
You should be able to disconnect all the LEDs strings and the TV should not go into shutdown.
BTW, the screen is edge lit from the left side and from the right side, and they run HOT!

[freakaftr8]

Re: haier le42b1380 power supply issue

ok thanks for that I just wanted to see if the power supply was going to shut down with the strings completely disconnected iS not obviously the problem. So now I just have to figure out why the power supply is shutting down

[freakaftr8]

Re: haier le42b1380 power supply issue

What exactly is the purpose of the other ic that looks like the led controller? Also the 8 pin regulator? Both located on the primary side of the power supply.

Btw one strip on the left one on the right and two on the bottom.

[freakaftr8]

Re: haier le42b1380 power supply issue

Bud do you know a quick and dirty way of forcing the power supply to stay on? I want to take some measurements but it's impossible to do this with how fast it comes up and goes down right now. If it blows up I'm not out much. Lol

by the way you will find the furthest most left strip on the side shorted out to ground as the aluminum heat sinks are a bad design and has a sharp corner on it as others have mentioned on this forum also. What I did is a used a piece of sticky tape to buffer the wires from touching the aluminum heat sink

[freakaftr8]

Re: haier le42b1380 power supply issue

has anyone come up with a solution to this power supply question? I'm getting 5v in standby and I can see that the main board is processing 5v down to the necessary 3.3 volts and others. just the 12 volt 24 volt audio processing and the LED voltage briefly comes up app on power up and then shuts down right away even though the power supply still active and the hot side is still boosting voltage until I turn the TV off.

[johnboy1313]

Re: haier le42b1380 power supply issue

Did you see post #40?

[freakaftr8]

Re: haier le42b1380 power supply issue

Johnboy. I saw your post. Interesting how with the econ unplugged the panel will not light but mine will not light either way just briefly along with the 12 volt 24 volt in lEd power. I'm more susceptible to thinking I have a power supply problem still as I have bridge the on panel with 5v and then I grounded it to see whether either would work and I still get a Brief Flash of the LED strips. so I'm thinking it's got to be power supply related. Hey if you want to part with that other power supply you have let me know

[johnboy1313]

Re: haier le42b1380 power supply issue

The one from the 50" Element? Yeah, it's just taking up space. PM me.

[johnboy1313]

Re: haier le42b1380 power supply issue

Just curious, how many LEDs are on each strip? How many volts are you seeing at each connector to drive the strips?

[freakaftr8]

Re: haier le42b1380 power supply issue

not sure on how many LEDs are on each strip unfortunately the TVs at work right now but I'm seeing about 38 to 40v DC on each of the four connectors of course 2 or wired in series

[tom66]

Re: haier le42b1380 power supply issue

If they are white LEDs it will be about 3.3~4V per LED.

[johnboy1313]

Re: haier le42b1380 power supply issue

Thanks to freakaftr8 for getting me the part numbers for the replacement driver ICs. My set is up and working now.

[LITEZONER]

Re: haier le42b1380 power supply issue

Hey all, i saw back in page one about voltage being in the 360 range on the main filter caps, i am getting just above 160DC at both caps, Is this an obvious issue? Main problem is no voltage to the LED Strings, Power comes on TV does not light, But Power will not shut off unless i unplug the set of course. Thanks folks, Much appreciated.

[budm]

Re: haier le42b1380 power supply issue

If the PS-ON is present but the Voltage on the main filters still stay at 160VDC, that means the PFC Voltage booster is not working.

[LITEZONER]

Re: haier le42b1380 power supply issue

Thanks budm, I appreciate it,

[wedg3]

Re: haier le42b1380 power supply issue

It's an old thread, but it's in the same way. Doesn't want to start a tread for the same reason. Have An HTX-PI420402A power supply. The TV on and Off rapidly all the time

-I unplug the right side stack of led and it's doesn't do anything
-I unplug the left stackof led and it all light up ok but 1 set doesn't light up
-I try to look at the led if something bad... but all led string seem good.
-I swap the led stack, led from left on the right IC side and the right side on the left power IC. All light up ok.. but smell like the IC won't work for long.
-No led - 45 volts on each Led driver connector. I know that they work in series.

My firts impression is that a stack of led draw to much current and one IC isn't able to light it up. If all led work... how can this be ?