Emerson LC320EM2 back lights on but no picture

[Gorrillasnot]

Hello,

I bought this TV for $20 at a rummage sale which I don't think is too bad if it's fixable.

The symptoms are I can plug it in and I get a standby light. Press the power button and the led blinks several times then goes out. Then the back lights turn on (and stays on) but no picture is shown. I also get sound.
I haven't had a chance to open it up yet, but I'm thinking its something in the inverter part of the board.
I searched on here to see if anyone else had similar issues with this TV but all I found were posts with no power issues.

any ideas?

thanks

[budm]

Re: Emerson LC320EM2 back lights on but no picture

If you do have backlights then inverter circuit is OK, inverter is for backlights to provide light source so you can see pictures on the LCD panel. It sounds to me that either the T-CON board is not getting the power from the main board, or SMD fuse on the T-CON board is blown, or the main board is not sending the signals to the T-CON.

[stj]

Re: Emerson LC320EM2 back lights on but no picture

if it was the invertor, the backlight wouldnt stay on.
maybe a psu problem - cant say until it's open.

[Gorrillasnot]

Re: Emerson LC320EM2 back lights on but no picture

I opened it up.
looks like the power and inverter are on the same board and the main and t-con on the other board.
No signs of obvious bad caps or burnt components.
not sure what to do next.

[stj]

Re: Emerson LC320EM2 back lights on but no picture

that's a clean layout.

it could have done with a heatsink on the main chip though.

did you check the connectors are in o.k. ?

[Gorrillasnot]

Re: Emerson LC320EM2 back lights on but no picture

I checked the cables and made sure all were firmly seated.
Also on the PSU I checked all the jumpers with a voltage labeled next to them. There were 3 or 4 21v jumpers and they measured right on. and I found one 3.3v that was also right on.

[stj]

Re: Emerson LC320EM2 back lights on but no picture

you see that board at the top-center,
i suspect that has a second connector on it you cant see.

the panel connectors are not on the edge - they are on the back.
that board probably acts as an extension cable.

[Gorrillasnot]

Re: Emerson LC320EM2 back lights on but no picture

i don't see any other connectors just by looking but i also haven't disassembled the metal frame yet either.

Do u think the issue is with the main/t-con combo board?

thanks

[budm]

Re: Emerson LC320EM2 back lights on but no picture

OK, this LCD panel may have integrated T-CON or T-CON is integrated into the main board.
Can you see the LCD panel number sticker? I need it so I look up the spec sheet of this panel.
I can seven LVDS pairs on the main board.
http://www.shopjimmy.com/media/catal...001-dm-top.jpg

I cannot find the info for UK32MXK LCD panel.

[Gorrillasnot]

Re: Emerson LC320EM2 back lights on but no picture

I can only find one sticker on the back of the panel and if I'm reading it right I think it is P/N UK32BXA

[Gorrillasnot]

Re: Emerson LC320EM2 back lights on but no picture

If the t-con is integrated into that top board does that means the TV is likely not fixable?

[budm]

Re: Emerson LC320EM2 back lights on but no picture

That is correct. So far no info about this LCD panel UK32BXA.

[Gorrillasnot]

Re: Emerson LC320EM2 back lights on but no picture

ugh! that sux..was worth a gamble though I guess

[Caleb]

Re: Emerson LC320EM2 back lights on but no picture

That power board is worth at least 40$ on ebay. Its a bit of a hassle but it would get your money back

[Gorrillasnot]

Re: Emerson LC320EM2 back lights on but no picture

yep that's what i was thinking. part it out and try to break even or maybe even make a couple bucks.

thanks everyone

[Gorrillasnot]

Re: Emerson LC320EM2 back lights on but no picture

I was tinkering some more with this TV and decided to take the metal frame off and get a look at the board that the LVDS cable attaches to.

There is what appears to be a voltage regulator at location IC5 in the pic.
It has 1117 written on it.
I tested it with the TV powered on and got the following readings 0.01, 0.04, and 0.72.
Does that sound like its ok?

Are there any fuses or other things I could check on this board?

thanks

[budm]

Re: Emerson LC320EM2 back lights on but no picture

So it does have T-CON on the panel, the fuse is the SMD green fuse on the left of the connector (CN1) with 20 printed on top (F21? marking on the board). There is also small copper pad with 'VDD IN' for incoming voltage test point.

[Gorrillasnot]

Re: Emerson LC320EM2 back lights on but no picture

With power on it measures 0.29v on both ends of the fuse and at the VDD IN test point.

[tom66]

Re: Emerson LC320EM2 back lights on but no picture

This means the main A/V board is not turning the power on or the T-con is shorted. Try checking both ends of the fuse to chassis ground for shorts.

[Gorrillasnot]

Re: Emerson LC320EM2 back lights on but no picture

I'm still learning..To test the fuse would I set my DMM to ohm and then with TV unplugged test each end of the fuse?

thanks