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BadGoo replied to Sceptre X505BV-FMDR No picture after backlight fixed

in Troubleshooting TVs and Video Sources

09-07-2015, 09:04 AM
Re: Sceptre X505BV-FMDR No picture after backlight fixed

Could it be a bad main board (now) or caps on it?

I'm just perplexed as it was functioning prior to the LED fix and the LCD came back on after being unplugged for a month. Are there any other options I may have?

I thought I was in the clear when I plugged it in and turned it on and it worked temporarily

Thanks...

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BadGoo replied to Sceptre X505BV-FMDR No picture after backlight fixed

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09-06-2015, 10:30 PM
Re: Sceptre X505BV-FMDR No picture after backlight fixed

I apologize for the delay. I recently moved and this unit was in storage.

I plugged it in the other day and the LCD actually came on and after about 30 seconds, I turned it off and back on to see if it would still work and I'm back to no picture.

Here are the readings of the voltage regulators. All I could find were generic datasheets for these particular ones.

Why would the LCD work before I replaced the back light LEDs and not now? Possibly just a coincidence?

...

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Last edited by BadGoo; 09-06-2015, 10:39 PM.
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BadGoo replied to Sceptre X505BV-FMDR

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08-23-2015, 07:32 PM
Re: Sceptre X505BV-FMDR

Same issue. I actually sourced similar SMD 2835 LEDs from China as I couldn't find the strip anywhere. I even contacted a few suppliers online that dealt strictly with back light strips. I put the new LEDs on the strip and they work fine except now I have an issue with the LCD not coming on which it did before. You can actually just test individual LEDs with a multi-meter. On the strip, there are small copper circles that I used to test each one.

It's been in storage for awhile as I recently moved so I haven't had any updates....

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Last edited by BadGoo; 08-23-2015, 07:37 PM.
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BadGoo replied to Sceptre X505BV-FMDR

in Troubleshooting TVs and Video Sources

07-12-2015, 09:24 PM
Re: Sceptre X505BV-FMDR

Sounds like a bad PS. When you say you have no way of turning the TV on, what do you mean? If you can turn it on, flash a light onto the screen and see if you can see an image (static etc)...

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BadGoo replied to Sceptre X505BV-FMDR No picture after backlight fixed

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07-12-2015, 09:14 PM
Re: Sceptre X505BV-FMDR No picture after backlight fixed

I've been extremely busy and haven't been able to diagnose the no LCD picture after replacing the backlight LEDs. It's on my list of things to do. I sourced the LEDs from Hong Kong (I believe the site was [url]http://en.honglitronic.com/[/url] )Re: Sceptre X505BV-FMDR No picture a...from Hong Kong...

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BadGoo replied to Sceptre X505BV-FMDR No picture after backlight fixed

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06-01-2015, 07:31 PM
Re: Sceptre X505BV-FMDR No picture after backlight fixed

Anyone have any other ideas?

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BadGoo replied to Sceptre X505BV-FMDR No picture after backlight fixed

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05-25-2015, 02:28 PM
Re: Sceptre X505BV-FMDR No picture after backlight fixed

All cables have been triple checked. I checked the DCV at the SMD fuse and I get 13V on each end of it (picture 3).

I'm just a little perplexed why it doesn't work now. I spent a great deal of time sourcing the correct LEDs for the back light and thought I was in the clear.

I've attached photos for reference.

Thanks for the help!...

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BadGoo replied to Sceptre X505BV-FMDR No picture after backlight fixed

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05-19-2015, 04:59 PM
Re: Sceptre X505BV-FMDR No picture after backlight fixed

I double checked all cables after the failed initial test. I unconnected them and reconnected them just to be sure. I suppose another check can't hurt and I'll go from there....

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BadGoo started a topic Sceptre X505BV-FMDR No picture after backlight fixed

in Troubleshooting TVs and Video Sources

05-19-2015, 01:31 PM
Sceptre X505BV-FMDR No picture after backlight fixed

I recently had 2 LEDs go out on the backlight resulting in no picture (however the LCD still had a picture when a light was applied to it) and I fixed the 2 bad LEDs (replaced them). Today I put the LED backlights in and they functioned correctly. However, now I don't get a picture on the LCD at all. All that comes on is the back-lighting. I've swapped out the PSU twice to double check.

I'm looking for any possible ideas or something that may stand out.

Thanks

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BadGoo replied to Sceptre X505BV-FMDR

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03-25-2015, 11:08 AM
Re: Sceptre X505BV-FMDR

I tested them out of the unit. Even @ 3.3v the original LED is much brighter than the ones I bought @ 3.3v. What directly affects this? mcd rating etc.? I don't mind buying LEDs to test, I'd just rather not have 100s of LEDs.

These are the two I tried first.
[URL="http://www.digikey.com/product-detail/en/0/516-2958-1-ND"]ASMT-UWB1-NX3B2[/URL]

[URL="http://www.digikey.com/product-detail/en/0/516-2681-1-ND"]ASMT-UWB1-NX302[/URL]Re: Sceptre X505BV-FMDR

...

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BadGoo replied to Sceptre X505BV-FMDR

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03-24-2015, 07:08 PM
Re: Sceptre X505BV-FMDR

I believe the package is PLCC-2. I grabbed a few to test out and they are close but not nearly as bright at the same voltage. Does anyone know what a typical LED rating is for LED Back lit TVs?

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BadGoo replied to Sceptre X505BV-FMDR

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03-14-2015, 04:37 PM
Re: Sceptre X505BV-FMDR

I've searched and searched for the LEDs and have come up empty. Does anyone have any other resources or a connection to get these? If I could figure out what LED is being used, I'd just rework it onto the strip.

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BadGoo replied to Sceptre X505BV-FMDR

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03-09-2015, 12:11 PM
Re: Sceptre X505BV-FMDR

Alright. Is it worth trying to replace the LED strips? At first look, I can't seem to find any LED strips online with the part number that's on them. Each one has 7 LEDs and a total of 10 strips.

2 LEDs are bad. The rest light up when tested. I highlighted them in the photo.

Thanks for the help!...

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BadGoo replied to Sceptre X505BV-FMDR

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03-07-2015, 03:53 PM
Re: Sceptre X505BV-FMDR

If the Back-light cable is unplugged, I get ramp up to about 300v then falls down to 7v in about 10 seconds and the same if it is plugged in.

As far as the BLon pin, I get nothing if the harness isn't connected to the main board. If it is, it's 3v at the PS and 4.5v at the main board....

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BadGoo replied to Sceptre X505BV-FMDR

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03-07-2015, 11:27 AM
Re: Sceptre X505BV-FMDR

Well, I replaced the PSU board with no result. At the connection that goes to the LED back-light, I'm only getting 7v.

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BadGoo replied to Sceptre X505BV-FMDR

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03-02-2015, 03:36 PM
Re: Sceptre X505BV-FMDR

bump.

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BadGoo replied to Sceptre X505BV-FMDR

in Troubleshooting TVs and Video Sources

03-01-2015, 04:55 PM
Re: Sceptre X505BV-FMDR

Alright. I've discovered something odd in my opinion. I was testing the connections here from the LED driver board to where it connects at the bottom of the TV. I'll try to explain it clearly.

When I disconnect FIG B. and test continuity of each wire, they all have continuity with ground and/or each other.

When I disconnect FIG. A (from the bottom of the TV), there is no continuity between the wires except similar (red, black).

FIG B. pins all test fine (no continuity except similar)
FIG A. pins all have...

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Last edited by BadGoo; 03-01-2015, 05:19 PM.
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BadGoo replied to Sceptre X505BV-FMDR

in Troubleshooting TVs and Video Sources

03-01-2015, 03:23 PM
Re: Sceptre X505BV-FMDR

And he delivered quicker than I thought! Ok. Here's the wiring.

EDIT: All voltages coming off the supply are correct....

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Last edited by BadGoo; 03-01-2015, 04:29 PM.
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BadGoo replied to Sceptre X505BV-FMDR

in Troubleshooting TVs and Video Sources

03-01-2015, 02:44 PM
Re: Sceptre X505BV-FMDR

I apologize for the no follow up. The person's TV I was attempting to fix gave up and he just notified me that he will be giving me the TV all together for me to attempt to repair and keep. I'll post photos of the boards connected within a day or two.

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Last edited by BadGoo; 03-01-2015, 03:17 PM.
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BadGoo replied to Sceptre X505BV-FMDR

in Troubleshooting TVs and Video Sources

01-18-2015, 09:48 PM
Re: Sceptre X505BV-FMDR

Sorry for the extreme delay. The friend who I'm doing this for put it on hold and forgot about it. Here's where I'm at now. I still need to test voltages but here are the photos. Visually everything looks OK unless I'm missing something. Indicator lights, sound and picture is working (minus the backlights)...

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