Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
I only plugged in panel and the IR sensor, nothing else
kevinallein
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Last Activity: 01-20-2022, 03:00 AM
Joined: 12-18-2010
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
I did this now at least 5 times without any change in behaviour. Also I cannot turn the TV off anymore through the control button....Leave a comment:
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
Debugging the 49 inch TV I am completely confused now. According to all I have found on the Internet the panel should receive VON / VOFF or VGH / VGL for the gate drivers (see attached block diagram).
On the main board I measured those voltages, please see the picture.
I can also measure VOFF on the panel test points and the connector to the panel. However I cannot measure the 28 V anywhere. How could that ever work ?...Leave a comment:
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
I just stuck the board into the 55 inch TV and it continously turns on and off. It shows the correct pic when it turns on, but it will not stay on continously.Leave a comment:
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
The second question for me is, where is the VON voltage on those connectors ? As far as I believe to understand the functionality, VON and VOFFE must be present at the gate drivers, which are integrated into that generation of panels, but what label is used for VON ?Leave a comment:
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
After the 55 inch worked stable with 3/4 of the panel I had it run for quite a while.
Later I worked on the 49 inch and put the 55 inch motherboard into the 49 inch TV. It seems like this did some damage to the MB, since now the 55 inch will not turn on completely again. Sometimes it starts, but than it will turn off again. When I measured this afternoon the VON voltage is also not present in the 55 inch MB now as well. Did sticking it into the 49 inch panel now damage that MB ?Leave a comment:
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
Looking at the logo on that blue scalar board, I thought this was not AUO ? Which logo is that ? The main board has the same logo....Leave a comment:
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
On the main board there is a VON test point and I do read 0 V, so there is a problem.
However I cannot see, how VON goes to the panel. In the pinouts from the Service Manual it does not list VON.
Also the circuitry on the main board uses two ICs from Richtek RT6936A and RT6935B and I cannot find datasheets or pinouts anywhere. I would assume, that that voltage is 0 due to some protection circuit ? Since all other voltages seem to be correct and also CKVx, CKVBx and STVP have the right high voltage,...Leave a comment:
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
Actually I just realized something: Since CKVx, CKVBx and STVP range from ~-10 .. 28 V, and there is a VOFFE with -9.4 V, should there not be somewhere VON / VGH with ~28 V ?
But what would be the label for this voltage ?Leave a comment:
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
I took now a bunch of measurements on those test points. Looks to me as if I do not have the same problem, since those measurements at least seem to be OK.
Can the experts please look at this ? Do I have a completely different problem ?...Leave a comment:
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
On the UE49KS7090 I am really confused. I have tried to block signals 12-22 (all CLK and CLKB) either on left or on right side with tape, but always get the same image now (see attached image).
That method seems to work for other people, what is wrong on my side ?...Leave a comment:
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
So I need to scratch off the protection paint before ?...Leave a comment:
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
But where would those test points in this pic be then ?...Leave a comment:
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Re: Samsung UE55KS7000 and UE49KS7090 main board protection mechanism
Can someone please help ? On the scalar board of the panel I see those two labels "VOFFE_-11V" and "VSS_-7.6V" and I thought, those could be observed on the two test points I marked with a white arrow.
However I found out, that those two test point connect to "VCOM2_CELL" and "VCOM3_CELL".
So where can I see the negative voltages ?...Leave a comment:
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Re: Samsung 4K led model UE50NU7445U no picture
Just to double check: You did block two pins, CKV3_MB4 and CKVB3_MB4 and still had lines ?...Leave a comment:
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Re: Samsung 4K led model UE50NU7445U no picture
I have tried to read up quite a lot over the last days. Apparently in modern panels the actual gate driver Transistors are integrated into the panel itself on the left and the right side. The external control turns on the gates line by line.
In case of a short on one side (e.g. left) that gate signal does not work correctly. However if you block the clocks on one side, the gate still opens on the other side (e.g. right). This might lead to timing violations visible in small bad lines, but at least the panel works ag...Leave a comment:
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Re: Samsung 4K led model UE50NU7445U no picture
Sorry, I guess I pressed to quickly...Leave a comment:
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Re: Samsung 4K led model UE50NU7445U no picture
And here is the Service Manual for the NU SeriesLeave a comment:
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Re: Samsung 4K led model UE50NU7445U no picture
Here is the same connector but from the NU Series Service Manual...Last edited by kevinallein; 01-08-2022, 09:09 AM.Leave a comment:
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Re: Samsung 4K led model UE50NU7445U no picture
I did actually find a NU Service Manual, that is probably more appropriate for you. Am I allowed to upload here ?...Leave a comment:
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