sony kdl-46xbr6 slow refresh

[CapLeaker]

Re: sony kdl-46xbr6 slow refresh

Not that this counts for anything, but I thought to let a brain fart go.
How about taking the Tcon board that works for 5 mins and reflow the bigger IC's on it? Did you try cooling certain ic's while the set is on?
Since the problem is over the whole screen, did you consider the other 2 big IC's in series that feed the 2 that are parallel?

[freakaftr8]

Re: sony kdl-46xbr6 slow refresh

I tried it this morning with the tcon that works for a bit. Reflow didn't fix. what I have noticed though is that the input voltage to the t-con board from the main board significantly drops when the board locks up . It's a short somehow it's really draining the voltage coming from the main board. Once it actually blew the fuse on the mainboard so it's almost as if a short to ground?

[bluetinc]

Re: sony kdl-46xbr6 slow refresh

I don't have any image problems right now, but I also didn't replace F603, and I have an external power supply for the Cayenne 1.0. I looks like uses almost 2A at 1V, and the whole set ran strong for over 24 hours now with the external power supply.

I spent some time looking at the power converter since it looks like it's going bad on lots of units, and the parts from my board to see what is wrong on my unit, and it looks like my high side Fet is bad. Oh, if the High side Fet is shorted, when the low side is turned on, you will get your power shorted to ground until the low side is turned off.


It also looks like the converter while just about cook book, isn't terribly efficient coming in at under 70%. The high side fet in itself is running over 600mW of losses itself without taking temperature rise into account. It looks like by trying to run the switcher at 1MHz combined with a 8% duty cycle, they are just hammering the parts with switching losses until failure.

New parts are on order, I'll keep everyone updated.

[freakaftr8]

Re: sony kdl-46xbr6 slow refresh

Would this be why the diode measures 30 ohms on the 1.0v? Because it's switched closed? I've found a shorted smd cap at the receiving end of the 1.0 a few weeks ago. Replaced it with no change.

[bluetinc]

Re: sony kdl-46xbr6 slow refresh

The diode looks to just be a protection diode, protecting from negative voltages or over voltage, and meters won't properly test it with the low impedance there (my board shows about 50 Ohms on the 1.0V core rail to ground). I would doubt that the diode is ever activated under normal operating conditions. I'm thinking that it would be unlikely that the diode would be going bad on TVs after so many years.

You probably need to the high and low fets off the board and check if they are good, and or simply replace them. Have you run the tv and watched the 1.0V core rail to see if it's drooping or something else strange going on?

Also, I'm curious if all these boards are failing at about the same number of hours running, is there an easy way to see the number of on hours from the Sonys?

[freakaftr8]

Re: sony kdl-46xbr6 slow refresh

okay so I have a new update I tried my good bored in a different TV and it works and it stays working so obviously the problem is either the panel or the main board on the other TV. Remember what was happening was this board was working in the other TV but it would only work for about 5 minutes and then the screen would freeze Up and would either go dark or turn into lines.

Interestingly though I purchased two refurbished T400hw01 v3 boards which are told to be compatible with the same BT2 bored but apparently they're not all I get is a black screen. Which leads me to believe that my other T400hw01 v3 board is fine because that one is producing a black screen on these TVs also but I was told that these two boards are interchangeable but apparently not for the XBR 6 Series there must be some screen change between panels or something. Now I just have to figure out why the other TVs walking off after 5 minutes I'm thinking more of a main board than anything else

[freakaftr8]

Re: sony kdl-46xbr6 slow refresh

The diode looks to just be a protection diode, protecting from negative voltages or over voltage, and meters won't properly test it with the low impedance there (my board shows about 50 Ohms on the 1.0V core rail to ground). I would doubt that the diode is ever activated under normal operating conditions. I'm thinking that it would be unlikely that the diode would be going bad on TVs after so many years.

You probably need to the high and low fets off the board and check if they are good, and or simply replace them. Have you run the tv and watched the 1.0V core rail to see if it's drooping or something else strange going on?

Also, I'm curious if all these boards are failing at about the same number of hours running, is there an easy way to see the number of on hours from the Sonys?

good call I have replaced all the high and low fats and I still have the same problem also replace the diodes and still have the same problem however the 1.0 Core voltage remain stable I have noticed so that the 3.3 volt jumps around a little bit not sure if this is related to the problem due to the fact that I have the slow refresh problem as soon as I turn the TV on

[freakaftr8]

Re: sony kdl-46xbr6 slow refresh

bluetinc would you advise replacing all 8 high and low fets on this board or just the four that operate the 1.0v core voltage? I only replaced the four fets on the lower half of the board. The working one I replaced all 8.

[freakaftr8]

Re: sony kdl-46xbr6 slow refresh

I have now figured out that the t400hw01 v3 tcon for the kdl-46z4100 is obviously not compatible with the panel on the kdl -46xbr6. even though all research on the internet shows that they are completely compatible all I get is a blank screen. I can wiggle the ribbon cables and get pretty colors on the panel which tell me that it's sending data feed to the panel but somewhere along the lines something is not right so that would explain why I have three of these t400hw01 v3 boards that do not work. Obviously they do work they're all doing what they're supposed to do but not compatible.

however I managed to repair one of the BT2 boards by replacing the whole voltage regulator supply circuit meaning all 8 high and low fet drivers and diodes and the 2 controller Ic's . the other two boards I still get the blurry screen slow refresh problem which in turn had reared its ugly head after replacing the blown F 603. I have tried replacing all the associated voltage circuitry like the good bored now but still there doing the same thing.

[freakaftr8]

Re: sony kdl-46xbr6 slow refresh

Do youguys suppose that this board has some kind of proprietary incorporated gamma IC? I'm only asking because looking at other threads it would appear that the gamma IC causes these kind of symptoms but of course there is no as15 on this board.

[strat1953]

Re: sony kdl-46xbr6 slow refresh

i have the same problem.but my question: if i remove both ribbon connectors from the t-con to the display,i still have a ghosty picture on screen. should i have NO picture with these two cables disconnected? does this mean i have a bad display??

[newtothis]

Re: sony kdl-46xbr6 slow refresh

Without tcon the screen will not display at all.

Bad Panel

[steves7839]

Re: sony kdl-46xbr6 slow refresh

Without tcon the screen will not display at all.

Bad Panel

Some panels such as the KDL-46XBR6 display white clouds, not a black screen, when disconnected from the T-Con. Sony T-Con training manual elsewhere on badcaps confirms this is by design.