Sony Bravia XBR-65X850B Clicking On and Off

[powerblackout]

XBR-65X850B tv clicks on and off constantly after power is applied, the status LED turns on white like normal, getting brighter, but then the power supply clicks and the status LED goes off.

POWER_ON 3.3V constant
T-CON_ON 0V until the "off" click where it blips up to 3V then back to 0V
REG12V is 12.6V until the "off" click, drops to 0V
T-CON_VCC12V is 0V until the "off" click, where it looks like the voltage goes up, my meter tries to get a reading but it goes back to 0V too soon.

I unplugged the two ribbons connecting the main board to the TCON board which let the tv turn on. i get sound using the menu button and the backlight turns on, but i do not get the test pattern on the display, it's all black.
T-CON_VCC12V and T-CON_ON are both 0V while those ribbons are disconnected, I would assume they would need some voltage to display the test pattern on the display though?

I replaced the main board, and the TCON board, same problem.

Does this sound like a TCON, power supply, or display problem?

[nomoresonys]

Re: Sony Bravia XBR-65X850B Clicking On and Off

quick test, try it with one tcon to panel ribbon cable connected then turn on tv, then try the other cable so one connected at a time, see if there's anything on screen, need to be careful that the end of the dis-connected cable does not touch anything like the metal chassis of tv during test, don't want to short anything out, best policy is to do all connecting and disconnecting with tv unplugged from power to avoid any errant surges and such.

[powerblackout]

Re: Sony Bravia XBR-65X850B Clicking On and Off

The TCON board has 4 ribbon cables that go to the panel, 2 up and 2 down.

When I only plug one ribbon in with everything else stock the TV comes on and the back light comes on. Here it what it looks like with only the top left ribbon connected.

I started adding in more ribbons one at a time, after I get to 3 ribbons connected it starts restarting and clicking like originally.

[powerblackout]

Re: Sony Bravia XBR-65X850B Clicking On and Off

Here is the top right and bottom left connected. I can hear a rapid clicking sound coming from the TCON board, possibly from one of the ICs.

[powerblackout]

Re: Sony Bravia XBR-65X850B Clicking On and Off

When I have any number of ribbons connected it will also randomly click off then back on again, sometimes a few seconds apart sometimes a minute or so.

There is a high pitch whine coming from the TCON board I picked up on video https://www.youtube.com/watch?v=PKkUfh0ThV4

I went ahead and did this same process for the replacement TCON board. when I only connect a single ribbon the status LED flashes yellow/green meaning it wants a firmware update, but Sony's website doesn't have it anymore..

[powerblackout]

Re: Sony Bravia XBR-65X850B Clicking On and Off

I found the update process for this tv on another forum: https://www.avsforum.com/threads/off...#post-33225713

after following those steps and getting the replacement TCON board firmware updated, the same problem happens with both now, clicking on and off no display.

[powerblackout]

Re: Sony Bravia XBR-65X850B Clicking On and Off

Along the bottom and the top of the panel are little tcon ribbon "jumpers". I removed the bottom left one and the TV started turning on with an actual image. Does this look like something that can be repaired?

[diif]

Re: Sony Bravia XBR-65X850B Clicking On and Off

It sounds like you've ripped of one of the flex cables. A photo will confyorm this.

[nomoresonys]

Re: Sony Bravia XBR-65X850B Clicking On and Off

can we see a picture of the "tcon ribbon "jumpers"?

[powerblackout]

Re: Sony Bravia XBR-65X850B Clicking On and Off

I have been very careful with all of the TCON ribbons, here are some pictures.

When the bottom left jumper is connected the board has the original symptoms. this was happening before i even opened the tv.

I pulled all of the ribbons out and wiped them down with IPA and a q tip incase there was any dirt on them.

[diif]

Re: Sony Bravia XBR-65X850B Clicking On and Off

The cable connects to a PCB, remove the metal shield that's covering it. There are components on the PCB, with luck you will find one shorted.