Haier LE55B1381 LED

[bjorkson]

Does anyone know the exact function of this board? What does it do, if it were to go bad?

HAIER LE55B1381 PC BOARD CV6M30L-B 27H1244-A

[selldoor]

Re: Haier LE55B1381 LED

Looks like a TCON to me lvds in from main board and lvds out to panel.

Without it back lights may still come on but jsut white screen or if only part bad
may show a corrupted picture colour bars or stripes

[tom66]

Re: Haier LE55B1381 LED

I would guess motion FRC. For 120Hz / 100Hz application. If you remove heatsink you can probably look up chip number, very basic frame interpolation, pretty rubbish.

[bjorkson]

Re: Haier LE55B1381 LED

Ok, makes sense. You think this board is bad? I was able to power on tv, backlight comes on, no display, picture or menu display. Already swap out main board, that didn't do anything. Was thinking this PC board might be the culpit.

[tom66]

Re: Haier LE55B1381 LED

Check pin 35, 36 for 12V of LVDS A & B.

[bjorkson]

Re: Haier LE55B1381 LED

Will check and test that tonight when I get home and report my findings. Thx

[selldoor]

Re: Haier LE55B1381 LED

I agree with Tom - I did say looks like - however the symptoms you describe would also apply to the Tcon.
If yours is the same as this
http://assets.shopjimmy.com/media/ca...26527b-top.jpg

it has a fuse on it that if blown will give a white screen.

[tom66]

Re: Haier LE55B1381 LED

Can give white or black screen with blown fuse, on modern sets typically black.

[bjorkson]

Re: Haier LE55B1381 LED

Sorry, had not had a chance to test the PC board, will check that out this week when I have more free time. Yes, that's the tcon board that I have on my tv set. Is there only one fuse on there? I believe F11, will test for continuity.

[bjorkson]

Re: Haier LE55B1381 LED

I measured the voltage on pin 35, 36 for 12V of LVDS A & B....getting both 12.6V for the pins. I also check the tcon board. It is the same one Selldoor attached a link to. 12YR_S128BMB3_4C4LV0.1, F11 fuse measured 3.1 V also.

I can see my backlight comes on, but just a black screen looking at the front of the tv screen.

[tom66]

Re: Haier LE55B1381 LED

F11 measures 3.11V, you sure?

[bjorkson]

Re: Haier LE55B1381 LED

Sorry...measured again. Put ground lead on the tv chasis and measure my f11 fuse again.

12.6 V DC
20v on AC

[tom66]

Re: Haier LE55B1381 LED

Only use DC volts for now.
12.6V both sides?
Pic of t-con board?

[bjorkson]

Re: Haier LE55B1381 LED

Yes 12.6v on both sides.

[bjorkson]

Re: Haier LE55B1381 LED

I just noticed my F11 fuse is label at 125V @ 3A...so at a 12.6V reading, does that tell me there is not enough voltage going through?

[tom66]

Re: Haier LE55B1381 LED

No way that T-con operates off 125V AC; the fuse is simply capable of interrupting current up to that voltage potential between open and closed circuit cases. Probably a case of that fuse being available for a low price when the unit was designed.

Also, voltage doesn't go through anything. Voltage is an energy level, similar to the concept of height, and is measured relative to a ground, like a height.

See attachment: test all points and respond with voltages at labels A-G. Then we can see if t-con is working.

[bjorkson]

Re: Haier LE55B1381 LED

Measure all the test points you label...here's my results all in DC Voltage

A=0
B=0
C=0
D=0
E=0.099V
F=0
G=0.202V

[tom66]

Re: Haier LE55B1381 LED

OK, you are sure that fuse is good? If so, try with the panel ribbons disconnected. If they still do not return it looks like a bad t-con board to me.

[bjorkson]

Re: Haier LE55B1381 LED

Yes, recheck fuse and showing 12.6 V, what an I checking when I disconnect ribbon cable from the panel?

[bjorkson]

Re: Haier LE55B1381 LED

Ok, I disconnected both my ribbon cable from the panel, turn the tv back on, and my ICG1 chip just smoke and Burnt up. Bad tcon board I'm assumming?