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Wannabe Geek

Topic # 227447 7-Jan-2018 16:55
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I have a 2011 model Sony Bravia KDL-40CX520


I wonder if someone has the knowledge to shed some light on what could be wrong with my Sony Bravia TV.


From the research I've done it looks as though the T-Con (Timing Control board) is the culprit. If this is the case then the TV is toast as Sony saw fit to mould the TC-Board into the LCD screen. In the other models the board is a separate unit.


Aside from the colours displayed at the foot of the screen as in the picture the TV is working normally. The colours appear on all settings and functions. I have tried the following:


Factory reset


Been inside and checked for lose cables


Sony haven't seen fit to update the firmware so this was not an option


An image of the fault is here:


Click to see full size


For what it's worth I've also attached the result of the Self Diagnostic test. According to the result there is no T-Con error. I've also read that an issue with Sony is that the board can be faulty but the diagnostic test shows that it's OK.



What I do get is









I'm still looking for an explanation as to what these mean but Google hasn't come up with the goods yet.




Thank you for any help.


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  Reply # 1931804 7-Jan-2018 18:56
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I have a 32 inch version of this model, and the screen on it is also failing  Although mine has some darker horizontal lines near the top, although not as visually bad as yours. Maybe just time to replace. In my case I think it is hardware related, rather than something that that a software update  can solve . Possibly a bad capacitor?. I thought the first thing that would fail on LCD TVs would be the backlights, but that doesn't seem to be the case based on LCD screens I have had fail..

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  Reply # 1931895 7-Jan-2018 22:54
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From what I've been able to glean from a few searches, the column on the right indicates how times errors have occurred, so in the case of P_ID_ERR that's 6 times. This page explains more but also references standby LED blinks. You've not mentioned if you're getting any of these but according to the picture linked on the page under "overview of standby LED blinks" errors in the range you describe are associated to "TCON control MT board" or "LVDS connection".


So, possibly the LVDS (low voltage differential signalling) cable is loose or faulty or, as you suspect, the T-Con board is at fault. If you think it's worth it, perhaps have a repair shop take a look. Should be a quick fault finding exercise with all the info you have.


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  Reply # 1931899 7-Jan-2018 23:43
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Would it be worth it just to buy a new TV? These days TVs aren't too expensive.

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  Reply # 1932000 8-Jan-2018 09:44
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I've got this exact same model, also bought in 2011 (from DSE), and I had a fault that sounds a lot like yours back in 2015. I rang Sony and they got me to drop it off at a repair place (can't remember their name, I think they were near Mt Smart but may be wrong). They assessed the fault and reported back to Sony and Sony agreed to supply the new part for free but I'd have to pay for the labour. I was happy with that as I really like this TV (it has 4 HDMI ports and I use them all, newer TV's seem to have only 2 HDMI ports and I didn't want to have to bother with an HDMI switcher). The TV has worked fine ever since (touch wood!)

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  Reply # 1932167 8-Jan-2018 12:05
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I also pay close attention to how many HDMI ports are on a new TV, and it seems like Samsung TVs usually like to have 3+, whereas Sony's are more 4 HDMI ports.

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  Reply # 1933037 9-Jan-2018 18:31
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Just might be a flaky LVDS harness, but quite a bit more likely to be panel itself, esp if symptom becomes worse after a few minutes. That model generation is pretty old for LCD now, and the CX520s had a CCFL backlight. Suggest something a little newer to replace it - if you can't stretch to a new set, look for a tidy 40EX720, 100Hz panel, LED backlight, 3 HDMI ports.

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