sony kdl 48R510c black screen after sony logo


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sony kdl 48R510c black screen after sony logo

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sparkyguy3809
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Aug 7, 2016, 7:36 PM

Post #1 of 11 (6144 views)
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sony kdl 48R510c black screen after sony logo	Can't Post

Sony Bravia KDL-48R510C
On startup, unit immediately displays "SONY" logo nicely. Immediately after that (maybe 1 second) the screen goes black (it is still faintly DARK grey, NOT shut off). I can still tell it has background illumination energized. "Power ON" LED is constant GREEN, no flashing codes whatsoever, no sound, no picture, nothing. Shut off and immediately back on will always go black immediately after SONY Logo. Power supply brick (19.5VDC) is fine. Unplugging TV for several hours to force a reset has no effect. Unit has the same problem on EVERY input source (and yes, I've tied them all and I'm certain they were connected to an active signal source). Same issue with either live OTA broadcast TV and both HDMI sources. Factory reset procedure . . . . . no effect. Attempts to enter factory service menu . . . . . no effect. Attempts to enter Self Diagnostic Screen Display . . . . . no effect. I'm a retired EE (not shy about digging out my test equipment). I located a pdf of the factory service manual on internet, and it initially indicated to replace the BA board. I located a replacement BA board and swapped it out. Results of new BA board were (you probably can guess it) . . . . . no effect. Any SONY repair techs got any suggestions? I'm finding that this is a pretty common issue with Sony Bravia KDL models, but most successful repairs are by sending the thing back to Sony. What "magic" and "secret handshake" is the factory service performing to repair these things?

jts1957
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Aug 7, 2016, 7:59 PM

Post #2 of 11 (6126 views)
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Re: [sparkyguy3809] sony kdl 48R510c black screen after sony logo [In reply to]	Can't Post

SELF-DIAGNOSTIC SCREEN DISPLAY works? (Page 12/13)

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Location: Far, Far Away

sparkyguy3809
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Aug 7, 2016, 8:27 PM

Post #3 of 11 (6116 views)
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Re: [jts1957] sony kdl 48R510c black screen after sony logo [In reply to]	Can't Post

jts1957,
Thanks for the quick reply !
That was one of the things I originally tried without success (see my first post).

That said, the remote control that came with with this set is Sony Model RMT-TX102U which does NOT have a button labeled "i+ (Info)" as noted in FSM. After some research, I found another forum thread which noted the equivalent button on the RMT-TX102U is the "DISPLAY" button located on top of the directional arrow circle in center of the remote. This is what I used as an equivalent to attempt access to the Self-Diagnostic Screen Display. Hopefully, this Is correct. (Frankly, I think I've also tried every other button as a substitute for the (i+ (info)" button in order to enter the Self-Diagnostic Screen key-sequence and none of them act any different.)

I did notice that the green LED on the front center-bottom of the TV does NOT flash at all when pushing either "DISPLAY", nor 5 nor Volume - buttons with the set in standby mode. However, the set eventually does turn on when the final TV POWER button is pushed. This is immediately followed by the SONY logo, then the screen once again goes black (again, all without any audio). Essentially, the set acts the exact same way as if I pushed the POWER button by itself.

Does any of this help for a possible next step?

jts1957
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Aug 7, 2016, 9:42 PM

Post #4 of 11 (6106 views)
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Re: [sparkyguy3809] sony kdl 48R510c black screen after sony logo [In reply to]	Can't Post

The four buttons have to be entered in a fairly rapid sequence.
IF all power sources are good - and BA board is definitely OK, then that would appear to leave the panel.

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Location: Far, Far Away

sparkyguy3809
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Aug 7, 2016, 10:49 PM

Post #5 of 11 (6099 views)
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Re: [jts1957] sony kdl 48R510c black screen after sony logo [In reply to]	Can't Post

Then I'm probably screwed.
I tried pushing them them faster, slower, etc. with same result.
When in standby mode, it's as if the TV doesn't even respond to the first 3 buttons in the sequence (I don't see green LED blink at all when any of the first three buttons in the sequence are pushed). The only action I see is the final "TV POWER" button which then powers up the set as if it was the only button I pushed at all. . . . . first, I get the SONY logo . . . . then black.

I know remote is working because the green LED on the TV set DOES flash if I try to push any of the first 3 buttons once TV is "on" with a black screen. (I realize this doesn't accomplish anything other than it confirms that the first 3 buttons in the sequence ARE sending a signal to the TV when pushed.)

I've also used an old quick-test method to see if IR remote controls are actually sending an IR signal by pointing them into the lens of a digital camera. Since the CCD's in digital camera's respond to IR, you can see the remote control blinking in the camera display.

I can confirm that the backlight DOES stay on, even after the logo goes black. It simply looks like it has lost all signal. Seems ironic the panel would be bad if the SONY logo pops right up bright and bold and will repeat when shut off and back on.

I'm certain a replacement panel is 99% of the cost of a new TV.
Sucks to say that the unit is only about 2-3 months out of warranty.
I hate to say it but . . . . .Toast???

jts1957
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Aug 7, 2016, 11:39 PM

Post #6 of 11 (6093 views)
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Re: [sparkyguy3809] sony kdl 48R510c black screen after sony logo [In reply to]	Can't Post

Quote

the TV doesn't even respond to the first 3 buttons in the sequence

Where do you see that written? Owner's manual? or Service manual?

BA board is 'New to you' as it was obtained via a "panel is cracked, but all boards were working" site?
or
BA board was obtained through Sony / Sony authorized part supplier?

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Location: Far, Far Away

sparkyguy3809
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Aug 8, 2016, 12:00 AM

Post #7 of 11 (6085 views)
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Re: [jts1957] sony kdl 48R510c black screen after sony logo [In reply to]	Can't Post

Sorry for being wordy...... I'm really frustrated with this thing and I might have been rambling a bit.

To clarify.
By my comment that you quoted, I was trying to note that the first three button steps did NOT make the green LED on the front of the set flash as they were pushed. I did not know if this was normal or not. I didn't see any response from the TV at all until the 4th button (POWER) was pushed.

Yes, the BA board I swapped was obtained from a "board recycler" and I was aware that it could certainly be a dud. However, the board model numbers are identical to the last digit and the TV malfunctions in an IDENTICAL manner with EITHER board installed. The odds of two identically bad BA boards should be very high unless Sony has an incredibly bad reliability factor on the boards.

jts1957
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Aug 8, 2016, 12:36 AM

Post #8 of 11 (6077 views)
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Re: [sparkyguy3809] sony kdl 48R510c black screen after sony logo [In reply to]	Can't Post

Look at the LED back light failure rates. They are pretty high irregardless of brand, screen size, model, etc.

You say you have the 'splash' at power on which since the tcon appears to be part of the BA board would tend to eliminate the panel.

I'd either make comparative voltage readings on BA board (at the various regulator ICs, for example), or IF you can determine which input is selected and active, try to troubleshoot for "No Video with x," where 'x' is Composite or plain old analog tuner, for examples.

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Location: Far, Far Away

sparkyguy3809
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Aug 8, 2016, 2:59 AM

Post #9 of 11 (6068 views)
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Re: [jts1957] sony kdl 48R510c black screen after sony logo [In reply to]	Can't Post

With the lower plastic cover removed, I can see that the back lights are staying illuminated even after the splash screen goes away. In any case, it appears like I'll need to do some board-level checking.

Also, I just noticed on page 24 of the FSM (for my model) that the BA board has a padlock symbol. The padlock symbol is described on page 14 as a part that contains "confidential information" and notes to "closely follow instructions when replacing. Are there some special requirements for replacing a BA board beyond what is shown in FSM? I'm quite familiar with self-grounding when handling CMOS circuits, etc.

jts1957
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Aug 8, 2016, 3:16 AM

Post #10 of 11 (6066 views)
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Re: [sparkyguy3809] sony kdl 48R510c black screen after sony logo [In reply to]	Can't Post

From Shop Jimmy:
"IMPORTANT: After replacing this board, you may need to update the software to the latest version. Please visit http://esupport.sony.com and download the correct version for your model and follow all instructions."

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Location: Far, Far Away

sparkyguy3809
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Aug 8, 2016, 3:34 PM

Post #11 of 11 (6063 views)
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Re: [jts1957] sony kdl 48R510c black screen after sony logo [In reply to]	Can't Post

Thanks for the firmware suggestion. As your reply came in last evening, I was writing an edit to my thread asking if that could be a possibility. Just in case, I found and downloaded the firmware. However, if I can't see the screen, I'll never get a chance to (or have a need to) install it.

In any case, I think I have to throw in the towel.
For the life of me, I've looked over the BA board with a magnifying eye-loop several times and I can't locate ANY of the points noted on the flow diagram for measuring & testing. I started on FSM pg 38 and the only thing I could locate was surface-chip chip-fuse F6000. I could not find any of the test points: JL005, JL6015, JL6016, JL6006 or L6017. I've never seen a FSM that notes points to test that aren't identified on the board.

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