hello, I picked this TV up for free and started to diagnose it. I assume either a main board issue or shorted LED's. When I power it on, my voltages come up correctly and the LED's light for a split second. Then the entire system shuts down. No voltage anywhere. I assume shorted LED's forcing the PSU into protect so I disconnected the LED connector, powered on again, and the same issue occurred. Voltages came up for a second and then everything shut down. Any ideas?
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You Can't Succeed Until You're Willing to Fail -
Re: RCA LED65G55R120Q No Backlight
Try disconnect powerboard from mainboard, turn it on see if backlight come on and stay on, always good practice to have tv unplugged from wall outlet before unplug any connector then plug tv in and try.Quit because THIS SITE LETS A ROGUE MEMBER TYPE ANY GARBAGE HE PLEASES AND THE POWERS THAT BE NEVER DO ANYTHING ABOUT IT SO HE NEVER QUITS. THEN YOU GET A PENALTY FOR RESPONDING TO HIS ATTACKS. BEEN GOING ON FOR WAY TOO LONG. DONE SUPPORTING A SITE THAT ALLOWS THIS BS. -
Re: RCA LED65G55R120Q No Backlight
Pictures of what we are dealing with will help.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: RCA LED65G55R120Q No Backlight
"When I power it on, my voltages come up correctly and the LED's light for a split second."
So what DC Voltages do you have on the control pins of the power supply board connector CN2: ADJ, BK, and PS?
What Voltages do you have on the LED connector pins with LED connector in place? You need to leave the probe on each pin and then Turn on the TV to see how high it goes up to then wait 5 seconds to see how low it goes down to, do that on each pin of the LED connector, black probe on the chassis GND, you have two LED (+) and two LED (-) so 4 tests total.Last edited by budm; 01-23-2019, 11:34 PM.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: RCA LED65G55R120Q No Backlight
Voltage checks are a must as budm has indicated. A year ago I had set from friend of friend with similar problem except logo displayed. Power board and LEDs checked out OK by forcing them on. That left me with likely eeprom corrupted on main board. That set 65" Polaroid similar to RCA was recently given to me and I will first be trying freeze spray on the eeprom.Comment
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Re: RCA LED65G55R120Q No Backlight
Sorry for the delay. I'm in WI and its been a rough week! Finally got voltages for you.
PS-5Vs: 5.1v always
ADJ-BK: 1.6v when turned on, drops to 0
5V+5V: 4.9v once powered on, then drops to 0
LED Connector (left to right)
+: 285V drops to 0 in five seconds
-: no reading
+: 135V drops to 0 in 5 seconds
-: no readingLast edited by zacheriaj; 01-30-2019, 04:59 PM.You Can't Succeed Until You're Willing to FailComment
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Re: RCA LED65G55R120Q No Backlight
This is the typical Backlight failure issue.Comment
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Re: RCA LED65G55R120Q No Backlight
The higher voltage string is showing the same symptom. By displaying 0V on the both (-) pins say the Backlights are faulty and if you want to fix it then you would have to open up the Panel and test the Backlight Strings.Comment
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Re: RCA LED65G55R120Q No Backlight
You count the pins wrong for the connector CN2. It has 18 pins total. The expose pins you see from the top side of the board are ODD number pins, the even number pin you will have probe from the bottom side of the board or via the wire entrance side of the connector.
Pin name assignment for example: Pin 17 is ADJ (DIM control), Pin 18 is BK (BL-ON).
1) So to troubleshoot the problem we will need correct data first.
2) I need the pictures of the bottom side of the power supply board to see if the two LED strings are connected in series or not.
This looks to be the same as your board:
https://www.shopjimmy.com/rca-re46hq...led-board.htm#
RCA RE46HQ2120 Power Supply / LED BoardNever stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: RCA LED65G55R120Q No Backlight
Hi, Any chance someone could post some high resolution pictures of the solder side of the power supply RE46HQ2120.
ThanksComment
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