Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

[withalligators]

Hi guys,
I'm a long time lurker but first time asker. Usually I'm able to figure out my problems without posting just from searching around and reading up. But anyway:

I picked up this fairly clean Sony KDL-52W4100 from an E-Waste bin a little while ago (with remote!). When you plug it in, you can hear a relay click, and then you can turn it on. The sony marquee below the screen lights up and the backlight turns on (although the screen looks grey with a lot of flashlighting). After a few seconds (although it might not be the same amount of time each attempt), it shuts off and throws a 14 blink repeating error code. A little research (I do not have the service manual) shows this is an LCD panel failure. I've also read that on these older units, the T-CON board is considered part of the LCD panel. Is this so? How does a panel go bad? It seems "fine".

I tried unplugging the LVDS cable going to the TCON and turning it on. It stayed on much longer and then shut off giving a 12 blink message.

Should I try replacing the (kind of expensive) TCON or is this a lost cause? Is there any troubleshooting I can do with the ribbons going to the panel to further determine anything? Do you much smarter folks have any better ideas?

Cheers,
Alex

[withalligators]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

Bump, anyone?

[tom66]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

Can you post some pictures of inside the unit?

[budm]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

Service manual:
http://elektrotanya.com/sony_kdl52w4.../download.html

[withalligators]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks



Would you like anything zoomed in on? Thanks! Thanks also for the link to the service manual!

[withalligators]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

Ok, so looking at the service manual, there is a separate listing for a TCON error which is indeed 12 blinks. So a TCON error is probably not the cause of the 14 blink error code which I thought might be inclusive. Any suggestions?

[tom66]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

Can you see a pin marked BL ERR going to the main board, from any of the inverter/power boards?

[withalligators]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

No, I can't. There is a BALANCER_ERR and an INV_ERR going from the G5 pb to the main though.

[tom66]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

Check the voltage of those, red probe on one pin, black probe on chassis of TV.

[withalligators]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

With the TV plugged in, and after it shuts itself off and throws the error, I set my multimeter to 10 DC. I got no reading on either pin. However, when I first turn the TV on, but before the backlight turns on, the INV_ERR jumps the needle to ~8 until the backlight kicks in, at which point it drops to nothing.

[tom66]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

The INV ERR is your fault.

You can take a 100 ohm resistor and use that to short it to ground, this will disable the error detect.

Then you should set up the TV on a full white screen and observe for any failed tubes (will present themselves as dim horizontal bars.)

If you find some, the transformer or bulb is bad, which is fixable. Transformer is most likely. You can run the set with a disabled bulb (obviously with faint line, though usually unnoticeable except on certain scenes) if you disconnect the transformer.

[withalligators]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

Awesome. I will run over to Radiocrap and buy a pack of resistors. I'll report back when I've gone farther.

[withalligators]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

Quick question, when you say short it to ground with a 100ohm resistor, do you mean
1) cut the wire going to the main from the G5 and attach the resistor/chassis-ground to the main side?
2) cut the wire going to the main from the G5 and attach the resistor/chassis-ground to the G5 side?
3) not cut any wires and merely insert one end of the resistor into the INV_ERR as it is plugged in and attach the other end to the chassis.

Sorry for what is probably a stupid question.

[tom66]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

Option 3.

[withalligators]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

OK, so, I stuck one end of a 100ohm 1 watt resistor into the INV_ERR pin, and the other end was connected to a screw in the chassis. I plugged it in and got the same 14 blink error code. I also tried sticking one end of the resistor into the GND pin directly below the INV_ERR pin and got the same thing.

[tom66]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

Check the voltage on INV ERR while you are doing this.

[withalligators]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

Ok, sat down to do this before I split. I can't seem to get any measurable reading with the resistor in there. Without it in there, I'm getting the same thing as before.

[tom66]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

OK; does the BALANCER ERR show anything with the 100 ohm installed?

[withalligators]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

no, nothing. Does the wattage of the resistor matter?

[tom66]

Re: Sony KDL - 52W4100 powers off after turn on, gives 14 blinks

No. I am thinking somehow BALANCER ERR and INV ERR are still getting through, maybe just a fast pulse. So perhaps try cutting the wires. On the main board end, attach them to ground, to disable the signal. Make sure you can reconnect them at a later date.