This tv is not even 3 years old. its a sony XBR-75X900H, it was like a flashbang went off suddenly, tv faded to black and no picture. backlight is on. tried to do the power cycle, factory reset. i get beeps from remote if i tap up/down but no picture. how can i determine if its the panel or a board? i have replaced boards before im just not sure what the issue is here. sony said nothing they can do and only suggested to find a local repair shop. please guide me here
-
-
Re: diagnosing sony XBR-75X900H. NO PICTURE
start with photos and measurements v, of the socket power boards to main boards... write down each pin assignment as the pin chart printed on the boards -
Re: diagnosing sony XBR-75X900H. NO PICTURE
I feel like I I’m completely under qualified here. I don’t even know what you want me to do lolComment
-
Re: diagnosing sony XBR-75X900H. NO PICTURE
PhotosAttached FilesComment
-
-
Re: diagnosing sony XBR-75X900H. NO PICTURE
I tried lookin in the sticky threads. I have no idea what I’m doing but I have a muiltimeter and I am a fast learner. Can someone point me to a write up of what to test?Comment
-
Re: diagnosing sony XBR-75X900H. NO PICTURE
first check the T-CON Fuse i marked it, if you have 12V DC on both side ,, with reference to TV chassis
if there are no 12V on it... take out the power boards and inspect the down side of it if there any remark of burn or spark as you described before.
if there are 12v on it from both side then you have issue on t-con or panelAttached FilesLast edited by Diah; 11-10-2023, 03:19 AM.Comment
-
-
Re: diagnosing sony XBR-75X900H. NO PICTURE
If your not sure what setting to have your multi meter on upload a picture of it and we will advise, also when testing try not to let the probes slip as you can short things out also remember your dealing with high voltage when working on the main power supply if your not sure of anything just ask before testing.Originally posted by tree5656 View PostComment
-
Re: diagnosing sony XBR-75X900H. NO PICTURE
Tv testing: https://www.youtube.com/watch?v=JWWmz-dbakY. lets skip the remarks about how this is an old tv that's being tested, he explains very well how tvs work.Comment
-
Re: diagnosing sony XBR-75X900H. NO PICTURE
I swapped the t-con and main board today to see if that would resolve. Now I’m getting no backlight so I will probably swap back and diagnose since I don’t believe that was the issue. I checked the fuse on the t-con board and it’s good. I will take off power board and inspect on the morning but I don’t see any visible damage. I’m really hoping it’s not a bad panel but I don’t even know how to diagnose that besides ruling out everything else. I get 4 red blinks now and nothing turns on.Comment
-
Re: diagnosing sony XBR-75X900H. NO PICTURE
a 4 blink code means either the backlight inverter board is bad or one of the backlights in the LCD panel has failed. It can also be the LD board or main logic board.Originally posted by tree5656 View PostComment
-
Re: diagnosing sony XBR-75X900H. NO PICTURE
Testing panel/tcon is pretty easy. I would do this first before anything else.
We need better picture of power board where the cables leaving the PSU to tcon are.
But essentially you disconnect the main board from psu, then disconnect the ribbons at the tcon coming from the motherboard. Then you take a jumper and jump stby/pw on/ tcon on/bl on all at once and then watch what happens to the screen. Also if there is a cable going from main board to a LED driver, disconnect that also.
Screen should then go red/white/blue/green as one solid color.
I would post those pictures first though so we can see the pins for PSU. But there is a few threads that show you how to do this. Including Nick's tv repair video on YouTube. Then you would know if it's panel or TCONComment
Comment