Voltage still applied to LED backlight stips when TV in standby?

**lmcancu** · 03-23-2023, 09:52 AM

Is it normal that a voltage of 54 volts is still applied to the LED strips when the TV is in standby? There is not much current, but I can see several of the LEDs are on but very very dim. When the TV is turned on, the voltage jumps up to about 100v (there are 33x3v LEDs, I removed 3 bad ones)

**Diah** · 03-23-2023, 10:52 AM

however you didn't wrote the TV type and model No. but i assume its first generation of LED Android TV.

**lmcancu** · 03-23-2023, 12:32 PM

Its an RCA RLDED 4331B: 43 inch LED TV (From 2015 I think). Not a smart TV

**Diah** · 03-23-2023, 01:09 PM

i see. its all in one boards. i think its just disorder at system power off / on. reset / hard reset could bring it back to normal / real power off.

**lmcancu** · 03-24-2023, 07:33 AM

Tried that and same issue, but one point I didn't mention is that I don't have the panel connected yet. I removed 3 LEDs from 2 of the strips (shorted them), so I have 33 LED lights instead of 36. The main board is just connected to power and the LED strips. The connection to the panel board (inverter board?) I haven't connected yet.
I was just testing to make sure that the LED backlights work. They light up when I turn the TV on after 2-3 seconds, but when I turn the TV off, I see that some LEDs are very dim and there is still voltage being applied.
Do I need to connect the panel for the voltage to go away when the TV is off?

**Diah** · 03-24-2023, 11:34 AM

its not good idea to jumper 3 Leds... it mean in total >=9V. and did the LED build in zener diode or with out..

so in short words now the system in DIY way... disorder of power OFF / ON accurate

about the screen.. did the T-CON integrated at Panel buffer boards in case yes... the point above will be in place.

**lmcancu** · 03-24-2023, 01:07 PM

Ok got it and thank you! I ordered new strips and was trying to make sure nothing else was wrong before they arrived. For the LEDs I removed, I just shorted positive and negative pads where the LED was with some solder. This shouldn't affect any zener diode protection in the strip?

03-23-2023, 09:52 AM	#1
lmcancu Senior Member Join Date: Oct 2009 City & State: Montreal, Canada Posts: 129	Voltage still applied to LED backlight stips when TV in standby? Is it normal that a voltage of 54 volts is still applied to the LED strips when the TV is in standby? There is not much current, but I can see several of the LEDs are on but very very dim. When the TV is turned on, the voltage jumps up to about 100v (there are 33x3v LEDs, I removed 3 bad ones)

03-23-2023, 10:52 AM	#2
Diah Badcaps Veteran Join Date: Feb 2013 City & State: SA My Country: Germany I'm a: Professional Tech Posts: 4,143	Re: Voltage still applied to LED backlight stips when TV in standby? however you didn't wrote the TV type and model No. but i assume its first generation of LED Android TV.

03-23-2023, 12:32 PM	#3
lmcancu Senior Member Join Date: Oct 2009 City & State: Montreal, Canada Posts: 129	Re: Voltage still applied to LED backlight stips when TV in standby? Its an RCA RLDED 4331B: 43 inch LED TV (From 2015 I think). Not a smart TV

03-23-2023, 01:09 PM	#4
Diah Badcaps Veteran Join Date: Feb 2013 City & State: SA My Country: Germany I'm a: Professional Tech Posts: 4,143	Re: Voltage still applied to LED backlight stips when TV in standby? i see. its all in one boards. i think its just disorder at system power off / on. reset / hard reset could bring it back to normal / real power off.

03-24-2023, 07:33 AM	#5
lmcancu Senior Member Join Date: Oct 2009 City & State: Montreal, Canada Posts: 129	Re: Voltage still applied to LED backlight stips when TV in standby? Tried that and same issue, but one point I didn't mention is that I don't have the panel connected yet. I removed 3 LEDs from 2 of the strips (shorted them), so I have 33 LED lights instead of 36. The main board is just connected to power and the LED strips. The connection to the panel board (inverter board?) I haven't connected yet. I was just testing to make sure that the LED backlights work. They light up when I turn the TV on after 2-3 seconds, but when I turn the TV off, I see that some LEDs are very dim and there is still voltage being applied. Do I need to connect the panel for the voltage to go away when the TV is off?

03-24-2023, 11:34 AM	#6
Diah Badcaps Veteran Join Date: Feb 2013 City & State: SA My Country: Germany I'm a: Professional Tech Posts: 4,143	Re: Voltage still applied to LED backlight stips when TV in standby? its not good idea to jumper 3 Leds... it mean in total >=9V. and did the LED build in zener diode or with out.. so in short words now the system in DIY way... disorder of power OFF / ON accurate about the screen.. did the T-CON integrated at Panel buffer boards in case yes... the point above will be in place.

03-24-2023, 01:07 PM	#7
lmcancu Senior Member Join Date: Oct 2009 City & State: Montreal, Canada Posts: 129	Re: Voltage still applied to LED backlight stips when TV in standby? Ok got it and thank you! I ordered new strips and was trying to make sure nothing else was wrong before they arrived. For the LEDs I removed, I just shorted positive and negative pads where the LED was with some solder. This shouldn't affect any zener diode protection in the strip?

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