Sony KDL 46XBR2 No Video but sound

[mike123333]

Hello,

I have a Sony KDL 46 XBR2 tv that stopped working, it has sound but no video. I have tested the voltages and everything seems to be fine off the PSU. there is an issue with my BES board and not constantly getting a 5 volt line, the voltage goes to 5.2 then drops to 0 then back up to 5.2V. this line feeds the TCON board. I have the TCON disconnected and still the same thing. I did manage to get the SM from here in another thread about the same TV and issue which did not conclude anything. looking at the schematics and the components what is in question is the switching regulator and Mosfet, the diode test fine, the capacitor test fine both in ESR and Capacitance. I would appreciate any help in identifying which is the culprit so can get the 5V back on steady so I can continue the troubleshooting. Would it make sense for me to inject a 5volts to that lien to test if that is the main issue?

The diode, inductor and capacitor for the 5 volt line are on the opposite side of the board.

There is no backlight , I did inject 5volt on the backlight signal and that brought the backlight on but was dim, so there is nothing wrong with backlight circuitry.

[mike123333]

Re: Sony KDL 46XBR2 No Video but sound

Can I assume that since the voltage is going from 0 to 5.2v that the mosfet is working and I have issues with the ic switching regulator. Unless the mosfet is not switching quickly . I see the voltage rise and drop is about a second apart.

[mike123333]

Re: Sony KDL 46XBR2 No Video but sound

I found what the issue was, I disconnected the TCON and the fuse was blown, took a 0.0005" wire and jumped the fuse and everything seems to come on, I have not hooked any videos to it yet, I want to replace the fuse what size fuse do I need, 2A or 3A? the TCON works off of 5V not 12V source. it seemed that the TCON gives feedback to the switching regulator.

[R_J]

Re: Sony KDL 46XBR2 No Video but sound

Replace it with the same value that was there before, there should be a letter on the fuse indicating the value. since you didn't post the t-con number I looked at shopjimmy. If it is a (T) thats 5 amp

[mike123333]

Re: Sony KDL 46XBR2 No Video but sound

Thanks for the quick response it is a T.

[EagleVideoGuy]

Re: Sony KDL 46XBR2 No Video but sound

Hi mike123333,
I have the same issue with my KDL-46XBR2 TV. I joined today, posted my information on the "greeting page", logged out and back in but can't seem to edit my profile. I've been trying to obtain the "Sony KDL-46XBR2 Training Manual FIX Direct-View LCD Television Chassis" at manual-archives.com, but MalwareBytes kicks in and not sure which links to take. I was trying to remove the heat sink and stopped, didn't want to force the issue. I was told to check the fuse, trying to find directions. Any thoughts?
My wife is in a rehab center. Fell backwards off the front porch 2nd step, fractured her pelvis and broke her wrist, so I'm kind of out mostly. Might need a new thread? Regards, Van

[EagleVideoGuy]

Re: Sony KDL 46XBR2 No Video but sound

I did have the manual already. The only indication of the T-CON board I can find is a photo called "Under Heat Sink", and all it has is a photo of the heat sink. Nothing I see shows removing the heat sink and the T-CON board. A T-CON board is not mentioned anywhere. I'm confused on that point.

[nomoresonys]

Re: Sony KDL 46XBR2 No Video but sound

https://www.youtube.com/watch?v=yTnkOfwBGGE Tcon testing, any fuse on the board will start with letter F. Hope your wife has a speedy recovery.

[nomoresonys]

Re: Sony KDL 46XBR2 No Video but sound

https://www.youtube.com/watch?v=SIggnQYW_1I