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Old 12-01-2017, 05:25 PM   #1
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Join Date: Oct 2012
City & State: Folsom, CA
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Default Sony XBR75X850C no picture backlights on

Received this from somebody and this is an interesting one.
By mishal symptoms were no picture no backlight and a flashing Amber and green light upon start up . Read up on the Internet about Sony and forced usb updates.

. So I did that And now I get back lights but still no picture. Upon inspection I notice that some of the voltage regulators and inductor coils are not putting out voltage on tcon. It would appear that as soon as I disconnect one of the 4 flat ribbons into the panel from the T con I lose my 3.3 volt . Is this some kind of a passive system where all cables need to be connected to create a closed loop circuit back to the feedback system of the tcon? I can only speculate that either this is a failure of the tcon board or panel.

All of the other posts I have seen on this forum in regards to this particular model that uses a Samsung 4K LCD panel point to panel fault.

So basically I'm wondering if for any reason something is not jiving with the LCD panel like a short circuit somewhere upon a ribbon driver it will not allow the tcon to initiate the primary voltages to drive the COF and FRC drivers

I have noticed that there are for M LCC capacitors on the far left of the tcon that seem to go short when the far right ribbon is connected to the tcon from the panel But there is no inherent difference between having all connected or one connected. Still the left side of the tcon seems to have completely dead voltages.

The only voltages I have notice being supplied to the panel are the 1.8 and 3.3 v. I believe there is a 17 v or something along those lines it supposed to also be applied and that's missing
Did I leave the soldering iron on?

Last edited by freakaftr8; 12-01-2017 at 06:29 PM..
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