Hi
Does anyone know what the DRC signal that is an input signal to the Power Board in LG OLED (and others I assume) TV's does?
Thanks!
ThomasX
Member
Last Activity: 07-01-2021, 06:26 PM
Joined: 06-26-2021
Location: Gothenburg
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LG OLED DRC signal
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Re: I refuse to give up ... (LG OLED65C7)
Yup, it's already on order
Will replace all those caps as well with new ones while I'm at it
I couldn't find any capacitors of the same package and value with a rating higher than 25V, which could explain the why it broke, as it's on the 24VD circuit.
I bet there's lot's of LG OLED TV's out there that got the TCON, and possibly more, boards replaced, just because a 5 cent capacitor shorted out.
Will replace mine for a higher voltage rating.Last edited by ThomasX; 07-01-2021, 06:21 PM. -
Re: I refuse to give up ... (LG OLED65C7)
That's what it said on the board just text to the F3 fuse, 125V/10A
The 24VD voltage is 24V 15A from the power board, considering the size of the TV and the light power with an all white screen, I'm not at all suprised
I'm more suprised the capacitor didn't blow before the fuse did, though
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Re: I refuse to give up ... (LG OLED65C7)
Capacitor was C956, but it's more or less just a coincidence it was that particular one. It could've been any one of 20 or so caps in the power area of the TCON board.Leave a comment:
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Re: I refuse to give up ... (LG OLED65C7)
Change the power board, they said
Change the mother board, they said
Change the TCON board, they said
I would've been ruined
I used what I had and changed C956 and F3.
Cost zero €, it was all in my "goodie bag"
And now the TV works again! YIHAAAAAA
It was a capacitor on the TCON board that had shorted, which in turn led to Fuse F3 blew.
Thanks for your support!
Took what I had, car fuses works in TV's too
...
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Re: I refuse to give up ... (LG OLED65C7)
Hi
Thanks for your responses! Much appreciated!
That service manual does not match my model nr precisely. But I have another one that does. However, strangely enough, the manual you link shows the VX1 in the correct position on my MB, while the manual I had before with the correct model nr, does not. Strange.
The VX1 voltage is as follows
Voltage across Resistor = 0 V
Voltage on both sides of the resistor vs GND = 1.37 V
It's unambiguous which voltages is ment.
...Last edited by ThomasX; 06-30-2021, 01:28 PM.Leave a comment:
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Re: I refuse to give up ... (LG OLED65C7)
Whoooopss!!!!!
It turned out I had disconnected the TCON ribbon cables in both ends, and not re-connected them at the TCON side when I put the MB back.
When I connect the TCON ribbon cables from the MB, I am back to the situation where the TV shuts off after 20 seconds. So that to me is a clear indication the problem is at the TCON or later.
So now the question is, how do I remove the heat sink plate from the TCON in a good way, without damaging the IC that it is stuck onto?
Thanks!Last edited by ThomasX; 06-29-2021, 06:52 PM.Leave a comment:
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I refuse to give up ... (LG OLED65C7)
... sooner or later someone will respond to one of my posts
My LG OLED65C7 turned black and quiet. When turned on, it stayed on for 20 seconds and then shut down.
I measured the power board voltages and signals, and the DRV_ON was 1.6 volts, but 24VT was 24V.
Then i removed both the MB and the PB to inspect them.
Put them back, and connected a USB mouse.
Then the TV turns on, and does not shut off after 20 seconds, it stays on.
And the DRV_ON is now 3.0V!
I am confident there is no issue with... -
Re: New LG OLED no display
I checked the power PCB and can conclude the DPC is an input signal to the power board. It controls at least a couple of things, one via an optocoupler.
Question is what it controls. Anyone got any clue?Leave a comment:
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DRV_ON = 1.6 volt on LG OLED65C7, fault?
Hi
DRV_ON = 1.6 volt on my LG OLED65C7, is this a correct voltage for this signal?
The TV turns on, the red led blinks three times, but after 20 seconds the TV turns off again without having shown anything on the screen.
The 24VD = 24 volts. -
LG OLED65C7 BGA issue?
Hi
I found some info that on some LG TV's there's an issue with the soldering of the BGA IC's on the motherboard, and that reworking them can solve the problem.
I have an OLED65C7 that's 3.5 years old lost picture and sound. The red led blinks three times, that's it.
I've measured the voltages and signals on the power board and it seems ok. Except maybe for two signals. DPC is 0 volts (should it be?) and the DRV_ON is 1.6 volts (should it be?), however, 24VD is there = 24V. I tried disconnecting the DRV_ON signal and then the 24VD = 0V, so it seems the DRV_ON... -
Re: New LG OLED no display
So now I wonder what is the DPC signal?Leave a comment:
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Re: New LG OLED no display
And now I noticed that with the DRV_ON signal disconnected, there's no 24VD, which leads me to think that DRV_ON = 1.6 volts is correct.
The behaviour of the TV is the same with the DRV_ON signal disconnected.Leave a comment:
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Re: New LG OLED no display
Well, I used my brain and realized first thing to try is to disconnect the DRV_ON and check the voltage level. So, with the DRV_ON disconnected, it still shows 1.6 volts. So that means it is the mother board that is driving 1.6 volts.
Is that maybe then the correct voltage for this signal, or is it the motherboard that is broken? I'm guessing the latter.Leave a comment:
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Re: New LG OLED no display
Hello!
I do recognize this is an old thread, but since there's some really good info here and it very closely relates to an issue I am having with my LG OLED65C7, I thought I'd ask here.
I have the issue with the red LED blinking 3 times when powered on, then staying off for maybe 5-10 seconds and then the TV turns off and the red led goes on again.
I have measured the following while the TV is on
24VD = 24 volts
12VT = 12 volts
20VS = 20 volts
12VM = 12 volts (7.4-7.8 volts when TV...Leave a comment:
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