KDL-37XBR6 has no picture but has sound

[JONESER]

Re: KDL-37XBR6 has no picture but has sound

Yes, backlight is on, has sound, vol/chan buttons work. Everything seems fine but no picture.

[Clydeuk]

Re: KDL-37XBR6 has no picture but has sound

Since the fuse on the TCON is intact try measuring the voltage at the fuse, usually 12v DC expected here, could be a PS fault, also Sony do use tiny SM fuses on the main boards, possible failure of one of these maybe?

[JONESER]

Re: KDL-37XBR6 has no picture but has sound

The tcon I just ordered, the guy said 100% tested and good. Either that tcon is bad too or it's a different problem.

[budm]

Re: KDL-37XBR6 has no picture but has sound

The key thing is to find out if there is voltage at both ends of the SMD fuse on the T-CON board or not first.

[JONESER]

Re: KDL-37XBR6 has no picture but has sound

I dont think the leads on my volt meter are small enough....

[JONESER]

Re: KDL-37XBR6 has no picture but has sound

So it should be on the TV and power on? Will I get the Shit knocked out of me if I touch something I'm not suppose to?????

[budm]

Re: KDL-37XBR6 has no picture but has sound

Yes, the TV has to be turned on, black probe on the chassis, red probe on the pad which is labeled WITH '12V IN', the pad is connected to the top end of the fuse F1, see if it has 12VED there, if there is, then put the red probe on the bottom end of the fuse and see if there is 12V there too.
Set the meter to 20VDC range.

[JONESER]

Re: KDL-37XBR6 has no picture but has sound

Okay, tried both tcon's and no power at 12V IN on either one.

[budm]

Re: KDL-37XBR6 has no picture but has sound

TV was turned on right, if that is the case, the main board is not sending the 12VDC to run the T-CON board.

[JONESER]

Re: KDL-37XBR6 has no picture but has sound

Yes, power was on. What's my next move?? The TV will power up, have backlight, sound, etc if the main board is jacked? I checked all connections in the whole TV too.

[budm]

Re: KDL-37XBR6 has no picture but has sound

"What's my next move??" Troubleshoot the very complex main board to find out why how the 12V from the power supply is fed to the main board and routed through electronics switch and then to the T-CON board. There are many SMD fuses on the main board.
Here is the service manual:

BTW, is there any blinking error light on the front panel?

[JONESER]

Re: KDL-37XBR6 has no picture but has sound

Cool, thanks a ton for your help!

[budm]

Re: KDL-37XBR6 has no picture but has sound

OK, check the fuse F1422 (5A/24V) to see if it is open and it does have 12Vdc on both ends of the fuse.

[JONESER]

Re: KDL-37XBR6 has no picture but has sound

Okay, got home from work and found the F1421 & 1422. They are on the underside of the board. Anyway, checked voltage and got 12v on the solders on the right. Got 12v on one side of the little fuse but not the other. How the hell do you change that thing??

[budm]

Re: KDL-37XBR6 has no picture but has sound

You leave the old fuse in place and stack up the new fuse on top of the old one. I hope you do have good soldering iron and know how to solder.
So the fuse F1422 is bad?
What you can do is to solder the small wire to each end of the fuse and then solder the wires to the standard pigtail (3AG type) 5A 125/250V fuse that you may be able to get from Radio shack or AUTOMOTIVE 5A blade type which you can get from car parts store.
You can scrape off the green solder mask on the board to expose the copper trace close to the ends of the fuse to get more soldering areas for the wires to solder too since that SMD fuse is very small.

[JONESER]

Re: KDL-37XBR6 has no picture but has sound

Yeah, I touched the meter positive lead to the top of the fuse (pretty much on the arrow) and got 12v. Touched the opposite side and got nothing. I can solder pretty good but my iron has a pretty big tip. Can I use this set up with a 10 amp fuse or a 7.5?

[budm]

Re: KDL-37XBR6 has no picture but has sound

Since there is smaller current value fuse on the T-CON board and it is OK, then you can use the 7.5A for now for testing.

[JONESER]

Re: KDL-37XBR6 has no picture but has sound

Well, I messed it up from my damn soldering iron. The tip was too big and I couldnt get it into the small space without touching other things...LOL

After I did all that, I just tried to jump the fuse to see if it worked until I can get a better soldering iron. Well, I'm guessing that something is touching that shouldnt be or something became unsoldered.... again, LOL.

When I plug it in, the power light comes on for a few seconds and it goes right to standby(red light blinking). I did find a write up from back in 2011 where a guy had the same TV, same symptoms and got it down to that same fuse. He jumped it and it worked fine. He ordered a new BU board since he knew that was the problem. I've been looking them up online and looking for the least expensive one.

Thanks so much for all the help!

[budm]

Re: KDL-37XBR6 has no picture but has sound

Too bad.

[jts1957]

Re: KDL-37XBR6 has no picture but has sound

When I plug it in, the power light comes on for a few seconds and it goes right to standby(red light blinking).

I don't think that is a description of sets standby mode.