Mulja tv repair portal
Equipment Repairs => LCD TV forum => Topic started by: Hwciua4i on March 26, 2021,21:17:52
-
Hi,
I have a Sony KDL55W800C which suddenly started showing horizontal lines moving up and down the screen. Initially, it would return to normal after a while but then it stayed for a few days.
So to troubleshoot, I tried to do a factory reset through the menu - but after I started it, it didn't complete and was stuck on a black screen for a long time.
Now when I try to boot the TV, it just shows the Sony logo and doesn't start the Android OS.
I tried the hard reset through the manual buttons (by pressing power + volume down and then plugging in the TV) - the TV turns on, shows the Sony logo and the light does turn green - but then it reboots and then just shows the Sony logo and goes black again.
Any help on troubleshooting and getting the TV back to regular working condition would be greatly appreciated. :sign0085:
Thank you!
-
You need a new main board - they drop like flies in W series. Then you'll need the firmware to activate the board. Sony boards don't come pre-programmed.
Bruce
-
Hi Bruce,
Thank you for the help.
Would changing the main board fix both issues? - going beyond the Sony logo - as well as fixing the horizontal lines on screen?
Also, would this be the part: https://www.electropartsonline.com/sony-55-kdl-55w800c-a-2071-530-a-main-video-board-motherboard-unit.html ?
Would you know any online store that would have a part like this in stock, as it seems to be out of stock on most sites I visited.
Thanks again!
-
Yes, I'd expect it to sort out the "hung up on logo" problem. not entirely sure it would fix the horizontal lines, but the problem is other than the main board, I'd expect it to generate an error code via blinking standby LED.
That certainly looks like the board for your model and its about half the price of a new board, plus it'll probably already have firmware installed. See if you can find the part number on your board - usually in small copper etching on the component side of the board. Bruce
-
Thanks again for the response -
I tried opening up it up to check the part number on the board - it says A2071530A on the white sticker on the top of the board (attached picture) though can't seem to find the copper etching of it
So I think the above link is the right part - I'll try to see if I can find somewhere with it in stock - every site I find seems to show it out of stock.
For the horizontal lines issue though, there wasn't any error code, as that issue had been ongoing on and off for a while till it finally became consistent at which point I tried to do the full reset and caused the hung on logo issue
-
Well, part number is correct and model number is correct, so go for it. It's reasonably priced but hang on - they say it's out of stock. Keep looking.
-
I managed to purchase a second hand board and do a firmware upgrade to pair and reset the TV to a working condition again.
However, the issue of the horizontal lines moving up and down the screen didn't get solved with the board replacement.
Any idea what might be causing it and how it may be fixed?
-
Horizontal lines- are they rolling down the screen or dancing in a segment of the screen? This may well be a display panel fault in the side tabs. Heard of the tape cut-off method. There are you-tube videos of this method of blocking 1 or 2 data lines at the t-con. I tried it once and saved an LG from the dump. Bruce
-
It seems to be more focused towards the bottom it does go throughout the screen - there are lines and flickers through most.
I've attached a video/photo and hopefully you can get a better idea from that of what's happening
-
Got you - looks like a panel fault to me. Check you tube for cut-off method.
-
Thanks again for the response
Is this the method you speak of: https://youtu.be/pfrRhw7-ZII
My panel doesn't seem to have a separate TCon board so I'm guessing it's the one ribbon cable that goes into the main board - and just tape up all except the first pin, then slowly remove tape and test each one by one? Once I find the correct pin, leave a tape just for that pin and the image should be more or less normal?
-
At the bottom centre of the rear you'll find a flat metal plate that the pedestal stand is supported by. T-Con is under that. A bit of work to get at because you have to undo the metal plate that holds the main board and move it upwards to access the screws for the T-Con cover. The link you gave is the correct one.
Bruce
-
Thank you
I finally managed to get some time to open it up again.
I tested with the Tcon panel and when I only had the left side cable in (the one to the left of the model number and sticker), the half of the screen worked without issues while the issues showed up when the other side was in by itself or both were in.
I tried the tape method a little with that side but it seemed to ignore the side entirely as if only the left side was plugged in.
Is this completely a TCon panel fault and could it be fixed by buying a replacement? The model number seems to be T550HVN08.4 CTRL BD 55T23-C0G (attached) - which if I'm not wrong is the same as :
https://www.amazon.com/Board-55T23-C0G-T550HVN08-4-CTRL-Logic/dp/B086SYBCR1?sa-no-redirect=1&pldnSite=1
or this
https://www.ebay.com/itm/284224845154?hash=item422d1ef562:g:88UAAOSwd3NdCPf2
Thanks again for your help.
-
You could try a T-con but what you describe when you alternately remove the panel flexies is enough for me to condemn the panel.
There is another option but it is irreversible. I did it to a Sony 55 last week with success. On the bad side you'll see some COFs embedded in the side of the panel and sticking out. Get a sharp razor and slice them off flush with the glass. That's it, so there's no going back afterwards. Bruce
-
Thanks again for the response.
Do you mean on the Tcon panel itself? Sorry, I'm not sure which part you mean to cut off
-
On each side of the actual screen there can be a series of COFs protruding a short way -they are fused into the glass screen with an end hanging out unattached.
Nothing to do with the t-con or strips along the bottom. these COFs have connections running inside the screen. You'll need to remove the cabinet front (bezel) to access them. Only do the ones on the bad side.
-
Thanks for the response again. I got some time to check the screen again but I'm still unsure as to what to look for.
By any chance, is there a youtube video or something showing the process you mean?
I also ordered another Tcon board - and the lines continued to show after replacing it unfortunately..
-
Could find nothing on youtube, but it's discussed a fair bit on Badcaps Forum.
-
Thanks Bruce,
I'll try opening a thread regarding the issue there.
But if by any chance you do get another Sony 55 to repair yourself - would it be possible to take a few pictures of which you mean and share them here?
Thanks again for the help
-
Sorry to report that I just stripped one today and it's gone to the recyclers, but I can report that it had NO side tabs, So scrap the idea of removing them. I would now venture to say that the panel has some internal fault, but just to be sure, check the data strips along the bottom of the panel for any shorted surface mount capacitors on the bad half. Both strips will have some similarities, so you should be able to do comparisons. You need to remove the black metal strip across the bottom of the panel (screws) and then remove the metal cover over the bottom strips to access them.
-
Hi Bruce,
Sorry I hadn't noticed that there had been a response - thanks for the help again, but so far no luck