Rca led50b45rq

[Gorrillasnot]

Re: Rca led50b45rq

Another strange thing is if i plug the tv in the red light comes on i hit power it goes out the tv then blacks out and i cant hit power again i have to unplug it from the wall. If i unhook the connector going to those LED pins i can turn the tv on and off.

I am a novice so I would probably wait on a reply from someone more experienced or possibly start a new thread, but if all your other voltages are normal, my bet is you have a bad LED string.

[budm]

Re: Rca led50b45rq

Another strange thing is if i plug the tv in the red light comes on i hit power it goes out the tv then blacks out and i cant hit power again i have to unplug it from the wall. If i unhook the connector going to those LED pins i can turn the tv on and off.

Remove the Female connector and then check the resistance between the chassis gnd and each pin of the Female LED connector to see if any one of the two shows resistance to chassis GND.

[fcisolutions]

Re: Rca led50b45rq

I've got this same tv (2 in fact) and I'm having similiar symptoms as zblad. I've got a red standby light and if the leds are plugged in, protection kicks in and shuts off the power supply after I turn it on. If I leave the leds unplugged, the main and power function correctly. So I tested the 2 strings of leds and sure enough one was bad. I then opened the panel and bypassed a strip of leds and now I get both strips to light with my shopjimmy led tester. The tester reads DCV 97.7v on 1 strip and 78v on the other. After putting it back together, still the same. I'm wondering if bypassing is not an option. I have been successful in the past but am wondering if RCA is different. Any ideas?

[budm]

Re: Rca led50b45rq

When you bypass that many bad LEDs the over current protection circuit will kick in.

[fcisolutions]

Re: Rca led50b45rq

This must be only for certain models as I recently bypassed a longer strip of leds in a Samsung un60fh6003.

[fcisolutions]

Re: Rca led50b45rq

So I had the same exact model come in after I attempted to bypass the led strip on the one mentioned above (I wound up cracking the panel so I scrapped it).

I harvested the leds and bam! This one I went slower and carefully replaced the strip and then put it back and sure enough the TV works great. Thanks again budm for the heads up and leading me in the right direction.

[jasonbay13]

Re: Rca led50b45rq

strange. i've got the same problem? but instead of 50b mine is 42c (42").

but the tv will not return to standby regardless of the led connector. and leds do not light or flash, but i also do not know how many are in series. i get 62v on all four led pins. (i've created my own thread, now on page 2)

[budm]

Re: Rca led50b45rq

So I had the same exact model come in after I attempted to bypass the led strip on the one mentioned above (I wound up cracking the panel so I scrapped it).

I harvested the leds and bam! This one I went slower and carefully replaced the strip and then put it back and sure enough the TV works great. Thanks again budm for the heads up and leading me in the right direction.

Please make sure to turn down the backlights level (not the brightness) to as low as you can to extend the life of the LEDs.
Glad you got it working.

[x_orange90_x]

Re: Rca led50b45rq

I have the same exact model with the same power board, however my issue is slightly different. When i plug the tv in the red standby light comes on. When i press the power button it turns off, however the blue light DOES NOT come on. There is no indication that the set is on.. No picture or sound. If i press the power button again the red standby light will come back on, and continuing to press power continues to switch the standby light on and off. I got this tv from my brother because he didn't want to fix it. The very first time i turned it on there was a very brief horizontal line that flashed along the upper-mid section of the screen, but since then this hasn't happened again. The caps and overall appearance of the main power board is excellent. I've considered the possibility of a blown SMD fuse or bad EEPROM, but I'm not certain of anything at this point. I can't seem to locate the fuse on this board either, however i haven't yet removed the entire black cover on the back of the board. Any help is greatly appreciated! Thanks

[budm]

Re: Rca led50b45rq

You can start by providing good clear hi res pictures of what you have, same model TV can have many versions of the circuit board, LCD panel, etc.

[x_orange90_x]

Re: Rca led50b45rq

Here is a picture of my tv model sticker, and a couple of the power board.

[budm]

Re: Rca led50b45rq

Can we see the whole back side of the TV showing all the boards so we can see how they are connected to each others?
https://www.badcaps.net/forum/attach...4&d=1489680896
Straight shot pictures of this top and bottom side of the board will also help so we can see the labels for the connector pins.

[x_orange90_x]

Re: Rca led50b45rq

I can upload them this evening. I'm at work right now and the ones i posted already are the only ones i took on my phone.

On a side note, i asked my question on FixYa earlier this morning and this is the answer i received: "Could be an open internal fuse of power supply falure"

I'm assuming they are referring to the SMD fuse.

[budm]

Re: Rca led50b45rq

Right now your power supply board is putting out at least the standby Voltage otherwise you will not have indicator lights at all.
We you will need to check the DCV at those two white connectors (not the AC input connector) and report the readings when TV is OFF and when the power switch is activated.
You need to put down the pin name and follow by the DCV reading for each pin so we can see what are there and what are not there.

[x_orange90_x]

Re: Rca led50b45rq

Here are pictures for you 😉

[dick_barton]

Re: Rca led50b45rq

What dc voltages do you have on those pins on picture 5 of 7

[x_orange90_x]

Re: Rca led50b45rq

Which pins do i probe on this connector?

[budm]

Re: Rca led50b45rq

All the pins except the GND pins which is where the black probe of your meter will be.
You must make sure to put down the pin name and follow by the Voltage readings.
You will be reporting the readings when TV is off and when the power switch is activated, you MUST follow the instruction to make it easier for us to help you.
We need to find out what Voltage you are missing on that connector.

[x_orange90_x]

Re: Rca led50b45rq

Ok, so i fear this was destructive testing ☹ i shorted the main plug with my multimeter.. And it went POP! (photo attached) However, now the tv acts a little differently. When i plug it in, the red standby light still comes on, but now when i press the power button i get that horizontal line i mentioned before followed by a quick flash on the screen. Also, pressing the power again now does not bring back the standby light as it did before. But the line and flash can be repeated everytime i unplug, replug, and turn the power on.

Anyway, as for the readings I got from that connector.. Everything reads 0.00-0.01 both in standby and with power on, except for +5VSB and PS-ON. Those are as follows:

+5VSB -- Standby 5.17V On 5.17V
PS-ON -- Standby 0.00V On 3.54V

Readings were taken AFTER i shorted the main plug, so I'm not sure if i made things worse or if they were like that before.

The burnt solder in the picture is the only evidence of the short I created, but i fear i have done much more damage than that.

[dick_barton]

Re: Rca led50b45rq

What are the IC numbers as printed on them.

What dc voltage do you have between the two legs of EC1 and EC1A when out of standby (On)