Re: Big Black Bravia
I agree with you, Tom66, it's time consuming!
For me this is an educational and experimental device, only because I was able to find the service manual and I believe in miracles.
It may become a TV again, one day, if I do the right bid.
I was unable to aloud so many pixels to go to the trash just because of something… very small. (and that's the problem)
I already have a TV that I almost never watch.
I use this think instead: [url]http://www.youtube.com/watch?v=y-jOcy7Wtbo&feature=related[/url]
I have...
Longbolt
Member
Last Activity: 07-31-2011, 07:48 PM
Joined: 07-06-2011
Location:
-
Re: Big Black Bravia
Buying and throwing, the logic gates of modern life!!
You have said clever things about AC OFF DET and how it works, but I do not understand what's make you think the PSU is bad.
Poker or crossword?...Leave a comment:
-
Re: Big Black Bravia
I have tried to pull it down but not up. I'm temped to try the 1K resistor pull up but since I'm not knowing what I'm doing I'm scared to kill something.
I tried to check the phfotocoupler on it's transistor side; diode test, when connector is unplugged it does not conducts collector-emitter, emitter-collector. Not shorted anyway, I assume it's OK.
When connector (on/off) to the main board is plugged diode test on the photocoupler terminals it conducts just one way.?!Leave a comment:
-
Re: Big Black Bravia
When you look at Q8601 and the zener diodes connected to Backlight. Should AC OFF DET be high or low on stby mode?...Leave a comment:
-
Re: Big Black Bravia
You should be right! Welcome.
AC off det has a lot to do with audio circuits but also with Backlight. I remember when I was forcing PSU to run and unplugging from wall I was hearing speaker noise after some seconds.
AC OFF DET comes from 5Vstby trough 22K resistor. A photo-coupler on the PSU board is charged to ground that signal.
If the readings I have are not good it will probably mess with the Backlight also....Leave a comment:
-
Re: Big Black Bravia
Nice of you to say that, I sometime wonder if a human being can replace one those components especially if they have more than two legs and is probably cheaper to buy a board than a iron for soldering and desoldering those SMT's .
Yes I do have them all right.
I finally found that resistor to pin 67 and I have 3.3V before it, so the processor is pulling it down. So when I pres power ON something is preventing it to go high.
I have 2.5V on the key connector. I don' know also what AC OFF DET means (which is...Leave a comment:
-
Re: Big Black Bravia
Now I have checked all the IC's on both sides of the BE and A2E4 boards that should have Stby power on.
Many of them have the proper Stby voltage.
Here is the list of the IC's that I “suspect”
BE BOARD:
IC 1003 (main processor)
Pin 41 – 0V normally 3.3V
Pin 45 – 0V normally 3.3V
Pin 49 – 0V normally 3.3V
Pin 12 – 1.86V normally 3.3V
Pin 62 – 1.13V normally 3.3V
Pin 67 – 0V (I can't locate the resistor that connects this pin to the 3.3V)
...Leave a comment:
-
Re: Big Black Bravia
Thanks, this is a good idea I will do that next week end. Just don't know how many of them I can check, there are IC's on both sides.Leave a comment:
-
Re: Big Black Bravia
I have never dreamed that I can fix that kind of thing on my own but I consider that I'm already watching one of the most exiting thrillers I ever saw on a TV
H1E is the buttons circuit, the TV can be turned on from those buttons.I do not have the remote.
H3 is the IR sensor board.
I have tried in the beginning to understand what H1E circuit does but I can't , it probably brings to ground the 2.5V on pin 24.
I do have 2.48V on pin 24
KEY is connected to the button Power ON/OFF ...Leave a comment:
-
Re: Big Black Bravia
I feel like a flywheel diode.
Switching between 4 windows of the same file, getting confused when switching between diagram and schematics and still around pin 67 and Q7419, Q8490; Q7415 and Q7416
Why on page 39 pin 67 seems to be connected to 3.3V stby terminal when I checked with the meter there was nobody.
I think that I understand something going to next window, question, goin back and so on.
And all this produces dumped oscillations inside my head, which I hope is positive.
Tomorrow I'll make a try with pen and paper...Leave a comment:
-
Re: Big Black Bravia
I have a small 10MHz crt oscilloscope if it can help somewhere. Tryed multimeter on 67th pressing power on... no hope.Leave a comment:
-
Re: Big Black Bravia
You have gone far with it !!! The circuit only of these 3 boards printed to A4 scale can cover 10.2 square foot.
I will try again with the PDF to night so I can better follow what you already know. I feel lucky
I checked the connectors, CN6200 & CN6201 on stby,
1st with everything disconnected and
2nd just one side of GE2 connected to PSU
I have the same readings in both cases;
CN6200 - 0V on all pins
CN6201 – 1.35V on AC OFF DET
On the CN8802
Pins 6, 7, and 9 are at 0
(if...Leave a comment:
-
Re: Big Black Bravia
The top of all caps looks even concave.
I appreciate your replays, all ideas are welcome.
I took the liberty to compare the circuit to a car;
if I have battery (the 5Vstby) to engage the starter (the relay), but I don't hear the starter running, why should I suppose that my engine is broken or that I have no gasoline.
And it's not because I see light on the board that means I have enough battery to run the starter
On the other hand I rarely shout at bad drivers because I never know how tall they are before they come out!...Leave a comment:
-
Re: Inverter board - red LED
I'm just inventing something for you so you can feel safe;
Here or somewhere else I red that on some televisions, and because the tubes have a lifespan manufacturers can put clocks or time counters so servicers can know if they should change the lamps.
As in a ofice lighting fluorescent tube they start to dimm and flicker because there is not enough current flow trough them due of aging of heaters filament.
So when your tube starts in the beginning gases are colder and is slightly under loaded so led can light, as it heats more current...Leave a comment:
-
Re: Big Black Bravia
The white one
...
Leave a comment:
-
Re: Big Black Bravia
Right, momaka, the regulator issue lead me to see that most of the output voltages on the regulator board are driven on and off by the big A2E4 board.
So let's suppose those are OK (at least one of the two I have now : )
The 17.5V that I have at 19V are regulated on the PSU.
I checked again with the multimeter where PSW MAIN and POWER-ON lead, and found pair of transistors on the back side (on the BE board) conectet to stby3.3V rail, followed the service manual Power is triggereg from pin 67 on main processor. I like this number!...Leave a comment:
-
Re: Big Black Bravia
I see also three others ways to proceed:
1- To go to the nearest bridge with my little daughter and let the TV fly! How exiting it will be!
2- To try to make a 40” funky table that lights up in the night, if I can make the lamps work
3 – To sell it to someone more experienced
But I'll wait for some advices firstLeave a comment:
-
Re: Big Black Bravia
Sorry the regulator boards are not bad the same way as I stated in my last post.
On the “new one” from e-bay a +9V pin is a alive compared to the my old!
The auction was saying “checked and taken from a working set”; shame for the TV!
Now - Should I stay or should I go?
With my little knowledge. But I'm fascinated looking at the schematics on the service manual, even thow is sounds like going
on a Japanese forum and trying to read! Anyhow I tried to be logic.
The history and situation;
1- The...Leave a comment:
-
Re: Big Black Bravia
When I press the power button on, there no signal send to the pin power-on.
When I send +3V on this pin the power board wakes up, but no backlight
There is 5V stby on main and video processor board.
I was suspecting the board between the PSU and main board, the GE2 (power supply regulator) because voltages were missing, so I ordered a used one from e-bay but nothing changed.
I marked with green the voltages I can read, with red those I do not have and yellow witch are not correct 19V instead of 17.5V
Are those boards...Leave a comment:
-
Re: Big Black Bravia
Hi, is no burn really, warm air deposed dust with the time. I agree on the 1st picture it looks scary!...Leave a comment:
No activity results to display
Leave a comment: