RCA RLDED4633A-C 46 LED tv - no video, no audio

[jackal68]

I'm trying to repair this RCA LED tv. It is a weird model as I could not get any information on it anywhere.

I have stand-by light (red) and when I turn it on, the blue light will come on steady (no blinking errors), but nothing shows up on the screen and no audio come out.

I opened up the cover and checked the ps...and all the voltages are coming out properly. I have disconnected the tcon board (both to the main board as well as the ribbons to the screen)....no difference.

I'm suspecting the main board, but I need help diagnosing it.

[paulstef]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

On the long white connector on the PSU you have 5V and 12V? And 24V on the smaller one?

Where is the pic of the inverter? Is the backlight working? What are signals going to the inverter board?

[budm]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

'I opened up the cover and checked the ps...and all the voltages are coming out properly"
Can you provide the DCV readings of all the pins on those connectors?
Also upload the pictures of the whole back side of the TV so we can see how all the boards are connected together.

[jackal68]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

This is a LED tv, so there should be no inverter.

I am attaching a picture of the connector and pinouts. The following are the reading on the meter:

24v reads 24.8v
5v reads 4.9v
5vusb reads 4.9v
12v reads 12.1
PS_ON reads 4.0v

[budm]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

How about the BK_ON (bl-on) pin of the smaller connector?
How about the connector with RED, BLACK wires on the power supply board? It looks like it is for the LED strings.
What DCV do you have between chassis and Red wire, chassis and Black wire?
That is a very strange looking back TV.

[paulstef]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

Ok, no inverter. The connector with the red/black wires goes to the backlight. Any voltage there?

On the other side of the board is there an SMD LED controller chip?

[jackal68]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

The following are the meter reading:

LED connector:

Chassis to black - 0v
Chassis to red - 95.5v
black and red - 95.5v

Smaller connector:

BK_ON - 3.9V
ADJ - 4.9V

as I said, I could not find information to this model anywhere....not just a strange looking back of a tv....

[paulstef]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

Did you do the backlight test?

If there are 95V and the two wires go indeed to the backlight then it should be on. Could be LEDs faulty.

[budm]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

OK, the LED driver is putting out Voltage, now remove the remove the connector and measure the pins of the connector on the board where the red wire connected to against the GND (CHASSIS), and the pin for the black wire and GND to see what you get.
More likely you have open circuit in the LED string some where.

[jackal68]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

After removing the connector and measuring the pins on the ps, the DCV are the same as before.

[budm]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

Can I see good clear pictures of the bottom side of the power supply board, especially around the LED connector?
You are going to have to open up the LCD panel assembly to get to the LED strings, not going to be fun.
Is this the TV you have? LED TV, sure. It is LED backlights TV.
http://www.rcatelecanada.com/item.as...mbr=RLDED4633A
http://www.walmart.ca/en/ip/rca-46-d.../6000068739119

[jackal68]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

Yes, that looks like the tv I have. As far as I know, it is LED...no?

Here are some pictures of the backside of the PS. the close up is of the LED connector (one pin on the negative and one pin on the positive.

I guess I will start the display disassembly tomorrow.....how do I start diagnosing the LED lights?

[jackal68]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

Okay...after taking the display out and finding out the LED light that was bad.....I bypassed it and got the light to come on......BUT....while putting everything back....I CRACKED THE SCREEN!!!

the tv is toast now...posting it for parts.

[budm]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

Oh too bad! So how many LEDs were bad?
I would keep the LED strips & boards for repair or for testing, and at least now you know how to figure out if you have bad LED drivers or bad LEDs.

[jackal68]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

I might keep it....but at this point, it is just a reminder that I screwed up!!

Only one LED was bad, so i just bypassed it....with the tv on, I can't tell the difference.

If it is not sold for parts, then i'll strip it down and keep the boards and strips.

thanks again for all the help!

[paulstef]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

I had this done recently, ripped of the tabs from the PCB that goes to the panel. I was thinking, oh funny noise and then saw that I also screwed up. :-) It was a super slim Sony LED TV.... :-/

[jackal68]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

yeah...that sucks!!

On a separate note, I am trying to find some data on this ic chip (DAP11H). I can't find anything on it and I can't find a place that sell it for a reasonable price (as I don't want to spend too much to repair an older monitor).

Thus, i'm trying to find the data sheet and see if I can replace it with something else.

Does anyone have any ideas?

Here is a picture of what it:
http://surimart.net/goods/goods_view...&cateCd=003009

[paulstef]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

I don't know what the "H" means.

You can get a lot of 10 pieces for $10 + $5 shipping on Aliexpress.

OR you can get the DAP11 version (without the H) on ebay.com.

[massagrabber]

Re: RCA RLDED4633A-C 46 LED tv - no video, no audio

RCA RLDED4633A-C 46 LED
I followed your solution (same problem). I have yet to dissemble and wonder what advice you would have to do it safely. one led was bad on one of the 5 strips? Should a strip be replaced & where is a parts source should I want one? Thanks in advance