Re: Sony XBR-65850F No Picture (Backlights/Audio Okay)
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philtvman
Senior Member
Last Activity: 12-28-2021, 01:27 PM
Joined: 06-27-2016
Location: Oklahoma
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Re: Sony XBR-65850F No Picture (Backlights/Audio Okay)
Here are some actual pictures of the screen with various panel boards unplugged. The black is a very true black. Left side, right side, and then just the side with the potentially missing diode....Leave a comment:
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Re: Sony XBR-65850F No Picture (Backlights/Audio Okay)
Was finally able to grab the TCON voltages, see attached....Leave a comment:
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Re: Sony XBR-65850F No Picture (Backlights/Audio Okay)
How can I be sure of this?...Leave a comment:
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Re: Sony XBR-65850F No Picture (Backlights/Audio Okay)
Correct, I had only disconnected the 'missing component' side at first. The picture I attached showed what resulted from the unplugging of the 'U' cables (all variations). I've attached another result with a diagram. Per the linked article though, it seemed that if there was a short or open somewhere on the driver board that the TCON in these sets won't power on completely.
I went through all the MLCC with an ohmmeter. The smaller ones all tested either 2-4k Ohm and the larger ones were all OL...Leave a comment:
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Re: Sony XBR-65850F No Picture (Backlights/Audio Okay)
What is the best method for testing MLCCs? Since this is a common failure point for this symptom.Leave a comment:
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Re: Sony XBR-65850F No Picture (Backlights/Audio Okay)
Attached is a closer up picture of the VCOM, VST, VGH lines, where exactly are the test points for them? I thought it would have exposed test pads.
There is also some variation between what happens when the driver boards are unplugged, I've tried all different variations. Regardless of what I do though, there is never a partial image. Attached is the result of unplugging the driver boards.
Thank you for your help, I really appreciate it....Leave a comment:
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Re: Sony XBR-65850F No Picture (Backlights/Audio Okay)
Sorry, I feel blind. Where are the labels?...Leave a comment:
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Re: Sony XBR-65850F No Picture (Backlights/Audio Okay)
Sorry to be ignorant, but how do I go about testing the voltages on the TCON board. I did notice that freakaftr8 was able to measure the voltages going from the TCON to the panel, but I'm not sure how to do that....Leave a comment:
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Re: Sony XBR-65850F No Picture (Backlights/Audio Okay)
I have attached a picture of the back and of the voltages. What is the best way to check the MLCC capacitors for a short or open? I went through them all with my multimeter in continuity mode. Would the apparent missing diode not be a cause for the TCON not processing correctly?...Leave a comment:
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Re: Sony XBR-65850F No Picture (Backlights/Audio Okay)
Disconnecting that side still has no picture unfortunately. The disconnected side is black obviously, but still no picture on the other side....Leave a comment:
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Sony XBR-65850F No Picture (Backlights/Audio Okay)
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Re: Measuring TCON Voltage through fuse
Yes, 12 volts coming through the connector and the TCON fuse shows continuity.
I’ll try the other steps when I have the set back in front of me, thank you!...Last edited by philtvman; 08-01-2020, 11:09 AM.Leave a comment:
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Re: Measuring TCON Voltage through fuse
No, I have 4.8 mV on both sides of the fuse. The TCON_VCC12V line that runs from the PSU to the TCON has 12 V on all terminals. Those lines feed into the connector that is the right of the LVDS ribbons.
Sony XBR65X850F for what it's worth....Leave a comment:
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Re: Measuring TCON Voltage through fuse
I'm getting like 4.8 mV through the fuse, but 12 V confirmed going into the TCON from the PSU. So I guess that is that....Leave a comment:
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Measuring TCON Voltage through fuse
Simple question, am I correct in assuming that a properly working TCON will show the 12V feed through the SMD fuse?
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Re: Samsung Ln55b650t1f Part Identification
Reply above, meant to quote it you...Last edited by philtvman; 04-13-2020, 02:52 PM.Leave a comment:
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Re: Samsung Ln55b650t1f Part Identification
No change in voltages when the T-Con was removed from the Main.
Also thoroughly looked over the Main/Power cable, everything looks good there.
Thanks for your help!Leave a comment:
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Re: Samsung Ln55b650t1f Part Identification
Yes, the backlights all come on with the main board disconnected.
INV-ON: 7.3
I-PWM: No wire in this connection
E-PWM: 4.9
Correct, the standby light will be on when the TV is OFF and turn off when the power button is pressed. It turns back on after about 2 seconds....Last edited by philtvman; 04-12-2020, 09:09 PM.Leave a comment:
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Re: Samsung Ln55b650t1f Part Identification
Are these the four you are referencing? Thank you for your patience!...Leave a comment:
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