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Old 11-24-2019, 10:30 AM   #1
bdorset
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Default TCL TP.MS6308.PB775 backlight current too high?

Greetings to all, Can anyone tell me how to reduce backlight current on this TCL TP.MS6308.PB775. The Board uses GB98AERN backlight controller IC. The original light bars are burn. It uses two bar in series. Each bar has six LED. The LED are 6V. The voltage across the two new bars 77V and 306ma current. The bars are getting hot in less than 5 minutes so I think the current is too high and the bars will burn soon again. Can anyone help?
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Old 11-24-2019, 10:53 AM   #2
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Default Re: TCL TP.MS6308.PB775 backlight current too high?

Thats your mainboard, I don't believe you can get it done on there, current mods are usually done on the powerboard by adjusting resistor values.
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Old 11-24-2019, 11:07 AM   #3
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Default Re: TCL TP.MS6308.PB775 backlight current too high?

Tomtech has some he did, there's a few more on the list to the right there, a schematic of your powerboard would help, no tcl's but shows you the gist of it: https://www.youtube.com/watch?v=GrfS...gtd-hcUXG2KjSC

Last edited by nomoresonys; 11-24-2019 at 11:08 AM..
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Old 11-24-2019, 11:32 AM   #4
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Default Re: TCL TP.MS6308.PB775 backlight current too high?

This is a single board TV, main and power supply together. I cant find an exact schematic for my TV but the attached schematic is very close. It uses the same controller IC in a different package.
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Last edited by bdorset; 11-24-2019 at 11:33 AM.. Reason: Made an error
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Old 11-24-2019, 12:10 PM   #5
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Default Re: TCL TP.MS6308.PB775 backlight current too high?

Ah, I see, my bad for assuming hate when that happens.

Last edited by nomoresonys; 11-24-2019 at 12:12 PM..
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Old 11-24-2019, 12:30 PM   #6
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Default Re: TCL TP.MS6308.PB775 backlight current too high?

I don't know how to do it, I think it would help with led lifespan tho, will be watching this one.
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Old 11-24-2019, 01:31 PM   #7
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Default Re: TCL TP.MS6308.PB775 backlight current too high?

I need to see high res pictures of the whole top and bottom side of the board and also close up of the LED connector to show how the wires are attached to the LED connector.
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Old 11-24-2019, 03:12 PM   #8
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Default Re: TCL TP.MS6308.PB775 backlight current too high?

Thanks to all who responded to my question and also to all who did some research but did not post a reply. I found the solution from many Russian forum. The solution is to change the resistor at pin 6 (ISET). The resistor on my board was 16.5K when removed. This resistor went from pin6 to ground. I replaces it with a 33K and the current drop to 150ma from 306ma and the voltage across the strips drop to 71V. I had to used Google translate to get the info because its all in Russian.
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Old 11-24-2019, 05:28 PM   #9
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Default Re: TCL TP.MS6308.PB775 backlight current too high?

Nice job, thanks for report.
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Old 11-24-2019, 05:38 PM   #10
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Default Re: TCL TP.MS6308.PB775 backlight current too high?

Did you get a picture of your fix?
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Old 06-03-2020, 03:50 AM   #11
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Default Re: TCL TP.MS6308.PB775 backlight current too high?

gb98aern from pin6 there is 2resistot remove one from them to decrise current
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