Re: LG 55UF6450 No Backlights
I just might try that Diah, This exact board is pretty hard to find.
I just might try that Diah, This exact board is pretty hard to find.
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Re: LG 55UF6450 No Backlights
Ok I sent my main board in to PTS Electronics for repair and they say they found nothing wrong with the board during testing so they are sending it back, should be here sometime today. Do I take their word for it or do I try Hot air on the BGA chip anyway?Comment
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Re: LG 55UF6450 No Backlights
dont heat or play any things with your main boards.. first of all i suggest you take the LCD in part till the LED, i am sure you will find the issue thereComment
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Re: LG 55UF6450 No Backlights
back a way, you did a test by unplugging the small cable on the tcon and the backlights came on. Can you do a similar test, but this time leave the small cable connected and disconnect both of the tcon to panel cable at the same time... what happens when you power up?Comment
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Re: LG 55UF6450 No Backlights
Per post #1: P-DIM1=0, P-DIM2=0 are 0V, but you have BL-ON signal (DRV-ON).
That small connector on the T-CON is more likely to be for dimming control, you are able to get the backlights to come on by disconnecting that small cable, you should then check the Voltage aging on those Dim control pins to see what you have.
Since you are able to get the light source to come on, then you should see pictures if the main board, T-CON board, and the panel are OK.
Can we also see the pictures of the whole backside of the TV showing how all the boards are connected together?Last edited by budm; 07-10-2018, 09:43 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: LG 55UF6450 No Backlights
Budwich, I disconnect both ribbons from tcon to panel and I get sound but no pic,no flash of backlights.Comment
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Re: LG 55UF6450 No Backlights
Budm, I get 3.26v on both DIM1 and DIM2 pins with small connector unplugged and 2.5mv on both pins when plugged in. Now that I got this main board back in I can not get the TV to switch inputs or find the DVD player, all I get is static sound for a while then it stops completely for a while then the static sound comes back on.Comment
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Re: LG 55UF6450 No Backlights
Pic of lay outAttached FilesComment
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Re: LG 55UF6450 No Backlights
Sorry the pic is upside down. Just a note here, there is a red light that is on steady on main board.Comment
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Re: LG 55UF6450 No Backlights
Well I have had the main board checked twice and it's working so I orded a tcon board and installed it today and I get the same issue, no changes. any idea's where to go from here? I also checked the backlights and all are working so they appear to be fine.Comment
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Hello everyone,
I am working on an ASUS ROG G513QY laptop with RX 6800M dGPU.
Originally, this laptop was completely non-functional. I replaced the motherboard (part number 6050A3254002-MB-Axx), and with the replacement board it started working fine.
For a long time, the dGPU worked perfectly stable. I played several hundred hours on very demanding games such as Cyberpunk 2077 without any crashes, instability, or detection issues. Performance was excellent and there were no warning signs of failure.
However, after some time, the replacement motherboard...08-25-2025, 06:09 PM -
Hello, I have a problem with my Samsung UE48H6410SSXZG with the main board BN41-02156A and the power board BN44-00709A. Everything seemed like this, the TV could no longer be switched on, the standby LED always flashed 5x2 times. Backlight was off and no sound from TV. Also made the flashlight test and there was no picture.
I made the following tests:
1. Disconnected the main board from Power Board = backlight works.
2. Connected the main board and disconnected the T-Con = backlights does not work.
So I ordered a main board from Ebay also BN41-02156A but from... -
Hi everyone I have this TV which was dead one day when I tried to turn it on. I've had the cover off and there was just a pulsating/electrical clicking/ticking noise from the PSU. I disconnected the mainboard as sometimes this works to just fire it up with backlights on? That didn't help. Same noise. Then I disconnected the backlight cable from the PSU and the TV came alive. It appeared to respond to the remote and i'm pretty sure it's fully operational when there is no backlight connected.
However, I am in a dilemma.
I tested the backlight outputs with the lights disconnected... -
I just removed the back cover to test the backlights because when I first plug it in it will flash once and then start dark but I can see the image. I got 131v on string 1 and 167v on string 2. Usually when I get a bad set the meter reads 300v and they won't light up. When testing, each set lights up inside the tv. When I plug in the power and check the leads with my multimeter both strings are only about 3v.
Does this difference in voltage between the strings indicate that the lesser has bad LEDs? Or is it normal that they are not the same voltage? I've read some about this tv and... -
Hi this vestel 65in tv had classic no backlights ,so nothing new there!
tested with b/l tester and the b/l seemed to be fine
so investigated psu 17ips72 (on this 65inch there are 3 fets and control iv type DB83630P)
did a thorough check on b/l circuit all ok .
When i tried again with b/l tester all ok .but then when i reinstalled psu all worked fine ,
could there be a component on psu that is causing the protection mode to stop b/l
.maybee causing it to be too sensitive?
it seems to me if the b/l have been on with my tester ,within a couple of minutes...
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