Sceptre X505BV-FMDR No picture after backlight fixed

[BadGoo]

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

[budm]

Re: Sceptre X505BV-FMDR No picture after backlight fixed

Did you hook up the T-CON board, the ribbon cables, the LVDS cable back in place?

[BadGoo]

Re: Sceptre X505BV-FMDR No picture after backlight fixed

Did you hook up the T-CON board, the ribbon cables, the LVDS cable back in place?

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.

[budm]

Re: Sceptre X505BV-FMDR No picture after backlight fixed

Next thing then is to find out if you do have DCV on the SMD fuse (at both ends of the fuse) on the T-CON board with ref to the chassis GND.

[BadGoo]

Re: Sceptre X505BV-FMDR No picture after backlight fixed

Next thing then is to find out if you do have DCV on the SMD fuse (at both ends of the fuse) on the T-CON board with ref to the chassis GND.

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!

[BadGoo]

Re: Sceptre X505BV-FMDR No picture after backlight fixed

Anyone have any other ideas?

[jetadm123]

Re: Sceptre X505BV-FMDR No picture after backlight fixed

check the voltage regulators, U2,U4,U6, on the mainboard.

[Myxologyst]

Re: Sceptre X505BV-FMDR No picture after backlight fixed

Can you tell me what LEDs you used? I have the same model TV with 4 bad LEDs and after search high and low cannot find the strips anywhere.

[BadGoo]

Re: Sceptre X505BV-FMDR No picture after backlight fixed

Can you tell me what LEDs you used? I have the same model TV with 4 bad LEDs and after search high and low cannot find the strips anywhere.

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 http://en.honglitronic.com/ )

[BadGoo]

Re: Sceptre X505BV-FMDR No picture after backlight fixed

check the voltage regulators, U2,U4,U6, on the mainboard.

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?



U1
1117 B
AD 1E3K
pin 1 - 0v
pin 2 - 1.25v
pin 3 - 3v

U2
1117 B
33 0L3Z
pin 1 - 0v
pin 2 - 3.3v
pin 3 - 5.07v

U3
1117 B
33 0L32
pin 1 - 0v
pin 2 - 3.28v
pin 3 - 5.1v

U4
1117 B
AD 1E3K
pin 1 - 0v
pin 2 - 1.25
pin 3 - 3.28v

U6
1117 B
AD 1E3K
pin 1 - 0.58v
pin 2 - 1.82v
pin 3 - 3.28v


UZ4
1117 B
AD 1E3K
pin 1 - 0v
pin 2 - 1.25v
pin 3 - 3.8v


Thanks
-Scott

[budm]

Re: Sceptre X505BV-FMDR No picture after backlight fixed

They look fine.

[BadGoo]

Re: Sceptre X505BV-FMDR No picture after backlight fixed

They look fine.

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

[ReeceyBurger123]

Re: Sceptre X505BV-FMDR No picture after backlight fixed

It could be a tab bond on the lcd that got damaged when you removed the screen to replaced the leds. Try flexing the panel slightly to see if any image comes up.