Rca led50b45rq

[x_orange90_x]

Re: Rca led50b45rq

Good, you have to open the panel next.

No that's not good 😞 I've seen a couple videos of LED replacement in other tvs, but they had Edge lighting.. Is it more or less difficult with rear-lit panels?

[Measuray]

Post 71:
"Just finished checking. I've got 171.8v on EC1 and 171.4v on EC1A. D4 diode reads 000 one direction and 461 in the other. I did the flashlight test and CAN see the menu on screen, so I'm pretty certain now its one or more bad LED backlights."
Post 148:
"Also decided to check EC1 and EC1A voltages without LEDs.. 397v on both. "
So after all these times I try to find out why we do not have Boosted Voltage after D4 was replaced.
At the beginning of the project we know that the PFC is not working so it has to be fixed first before moving on to other section if the TV is still not working after we get the boosted Voltage to run other circuit. So I spent times tracing the board to see if we have the VCC to run the SMPS IC and the PFC IC or not, But in fact the PFC does work after D4 was replaced but something else caused the VCC to the SMPS and the PFC IC to drop out so now we will need to find out if the SMPS for the LED driver, LED wiring (shorts wiring to the chassis?), or LED are causing the shutdown or not since now the SMPS does have the Boosted Voltage to run. If I would have known that we do have Boosted Voltage after D4 was replaced then I would have check other section of the circuit to find out what causes the shutdown to occur.
But I have to take a break from this threads for now since lately I have been given wrong DATAs from so many threads and caused me to go the wrong direction and it is getting very tiring for me. I am very patient person when trying to help people but right now I am very tired.

I hear you Budm - I had to pop 3 Prozac pills trying to follow this lead. Hope y'all figure it out.

[Measuray]

No that's not good 😞 I've seen a couple videos of LED replacement in other tvs, but they had Edge lighting.. Is it more or less difficult with rear-lit panels?

Orange90 - Did you figure the problem out? Personally, when I encounter a bad led, you can tell when it flashes a horizontal lines in the middle of the screen for a spit second. Then I open up the panel (best to find a large cardboard so you can slide under the glass to prevent breaking) and turn it on or test with a LED tester or my multimeter. You can also take a volt 9 battery and connect to pins to the opposite ends of the + and - ends to see if LED lights up.

[FDray]

Re: Rca led50b45rq

This is an old post, but I have found the fault of the RCA LED50B45RQ The fault is, if just one LED is shorted it will send a shorted shutdown signal to the main board to power down. I have never seen an led TV shutdown with just a 3.8 volt drop, I believe it is the amp rise that causes the fault. To find the ( maybe just one) LED, swap the known good strips (left or right side) that light even just a second before power shutdown, with the side that is unlit. when you move the bad strip to the side that lights it will fault. To find the bad LED use a 3 volt dc supply with pin probes ( this can be 2 AA battery's or one 3 volt button cell) and test starting from the connector end from + to - all the LED's down the strip. There are test points on both sides of each LED ( positive side is always to the connector end). There are video's online that show how to remove and replace smd LED's with a heat gun. The led's I use as replacement on most LED tv's are LED LUXEON NEU WHITE 4000K 2SMD from DIGI-KEY. Hope this helps someone to find this crazy shutdown fault in this LED TV.

[FDray]

Re: Rca led50b45rq

I forgot to add, this is the easiest LED TV to work on I have ever seen. Just remove the screws on the outside back all the way around. Then remove the screws from the T-Con/LCD connectors lift the back. The LCD panel is in the front case.

[FDray]

Re: Rca led50b45rq

No that's not good 😞 I've seen a couple videos of LED replacement in other tvs, but they had Edge lighting.. Is it more or less difficult with rear-lit panels?

I hope my reply wasn't too late, this is a great TV to be lost to a landfill. It's an easy fix with a 50 cent or less SMD LED. The whole LED strip on Ebay is around $15.00. Like everyone else here I always look for dim or dead LED's on the strip, This is not the case on this TV, the slightest amp rise on just a single LED cause's the main board to shut down. The way the LED strips are connected, if one led goes bad on a strip, the whole bank on that side shuts down. This makes it a "swap and try" method just to find the bad LED.

[x_orange90_x]

Re: Rca led50b45rq

Very very long delay I know, now that I've just gotten around to this one again. I pulled apart the panel and checked each strip of LEDs (which are all independent it appears). Only one wouldn't light. I removed it and after further testing found that only one single led is bad. I found a replacement on eBay, but I really don't know how important panel numbers and .1v really is.

The strip I have in my tv is 3.6-3.8v 76-781m and my panel number is V500HJ1-P01-12v.

The strip I found on eBay is 3.5-3.7v 74-761m and panel number is V500HJ1-PE8-12v.

Both mine and the eBay strip have the exact same model number of IC-A-KJAB50D354.

https://rover.ebay.com/rover/0/0/0?m...2F183749332905

Would this be a compatible replacement?

[nomoresonys]

Re: Rca led50b45rq

Should work, the model number you describe starting with IC-A is what to match up.
IC-A-KJAB50D507 will also work.

[x_orange90_x]

Re: Rca led50b45rq

Just a quick update on this..I replaced the strip with the bad LED and its working great! Unfortunately this TV doesn't have a dedicated backlight setting so I can't turn it down... But I did set it to Power Save which reduced the backlights.

However, it's now working and that's great news since it's been sitting in my basement for about 3 years

Edit:
In reply to the previous comments about not knowing which strips contain bad LEDs...I took two 9v batteries and connected them together (staggered, as in + to - looking like a Tetris piece), then connected a positive and negative lead to the opposite ends and touched them to the appropriate pins on the LED connector. The LEDs in a single half-strip amount to about 21v and two 9v batteries is 18v and is enough to light up the strip. Each strip in this TV independent, so this method works for every individual strip.

[neilc6]

Re: Rca led50b45rq

You should be able to turn down the backlight in the service menu under Panel Settings.

With tv on, try menu-1-1-4-7 or source-2-5-8-0

I would set to 55 and check every input. You are guaranteed repeat failure with the backlights running at 100%.

[x_orange90_x]

Re: Rca led50b45rq

You should be able to turn down the backlight in the service menu under Panel Settings.

With tv on, try menu-1-1-4-7 or source-2-5-8-0

I would set to 55 and check every input. You are guaranteed repeat failure with the backlights running at 100%.

Thanks for the tip! Menu 1-1-4-7 did it. It had 3 different backlight setting, one was just Backlight and was set at 50, the second was Normal Backlight and was set at 10, the 3rd was Power Save Backlight and was set at 50. 100 is actually least backlight and 0 is Max. So that means Normal was at 90%!!! I set all three settings to 45 which would be 55%, and it's plenty bright.