Orion tv-32082 dead

[tn245]

Hi! First I just want to say this forum is amazing! You've already helped me loads before I've even posted so thanks!

I'm working on an Orion 32" LCD model tv-32082. Symptoms are one day it just stopped turning on. No standby light - nothing. Just dead. I'm hoping you can help me find and fix the problem and maybe learn something in the process.

Everything looks good inside. No obviously bad caps and all fuses are fine.

The power supply board is CEF286A and the main board is CMF108A. As you can see in the pics, the backlight inverter is on the PSU board. I've been unable to find any schematics for these boards and the pins are unmarked so I am having trouble testing and debugging where the problem might be. I don't know which pin is PSON or BLON so unable to properly test the PSU so far.

I've included pictures of the open TV, the two boards, and close-ups of the connectors between them.

There is 3.3V present at the switch panel, and 5V at the remote sensor/power LED board.

On the attached file Connectors.JPG, numbering the pins on all the connectors from left to right, Voltages measured are as follows. (also measured when power button depressed, but only one pin changed)

-- (connector to remote sensor/power LED board)
1 0V
2 0V
3 5.17V
4 0V
5 5.1V
--

-- (to PSU)
1 0V
2 0V
3 0V
4 0V
5 0V
6 0V
7 0V
8 0V
9 0V
10 0V
11 0V
12 0V
13 0V
14 5.17V
15 5.17V
16 5.17V
17 0V
18 0V
19 0V
20 0V
21 0V
22 0V
23 0V
--

-- (to PSU)
1 36.3V
2 0V
3 0V
4 0V
5 0V
6 0V
7 0V
8 0.24V
9 0.24V
--

-- (to switch panel)
1 3.3V / (0V when power switch pressed)
2 3.3V
3 0V
--

Any ideas? I can provide more pics if needed.

Thanks!

[tom66]

Re: Orion tv-32082 dead

You don't need to know where PS ON and BL ON are, you can just power on the TV and measure the main connectors going to the main board. The voltage change should be noticeable on one of them, IF the main board is working properly.

[tn245]

Re: Orion tv-32082 dead

Thanks for your reply tom66. That is what I did, there was no voltage change on any connector when pressing the power button.

Faulty main board then?

[tom66]

Re: Orion tv-32082 dead

Most likely -- there are some voltage regulators on it that you could test
https://www.badcaps.net/forum/showthread.php?t=22231

[tn245]

Re: Orion tv-32082 dead

So, I've attempted to follow the instructions in that thread with what I take to be the regulators on the board. Having trouble finding datasheets for them though.

On the attached images the ICs are numbered 1-6 and the ICs and measurements are:

1 & 2
OOBCOW
72 79
Both have 0V to all 4 pins

3
KIA
78D05F
711
0V to all 3 pins

4
BD7820
73 40
Pin 1: 2.52V
Pin 2: 2.58V
Pin 3: 0V
Pin 4: 1.82V
Pin 5: 0.75V

5
BD7820
73 40
Pin 1: 2.59V
Pin 2: 2.66V
Pin 3: 0V
Pin 4: 1.83V
Pin 5: 0.74V

6
BD7820
73 40
All 4 pins 0V

Am I doing this right?

[tn245]

Re: Orion tv-32082 dead

Just to update for anyone interested or having the same problem. I got hold of another main board. Most of the main boards available compatible with this model are CMF108B as opposed to CMF108A which was originally in this set. I had to cut and drill some of the metal socket plate as the CMF108B has a slightly different socket layout.

Anyway, after putting it all back together it works perfectly.

Thanks again!