Sony KDL-65W850A Dead

[budm]

Re: Sony KDL-65W850A Dead

What you can do is to go out and buy a couple White LEDs and use your meter to test it to see what it shows on your meter.. Connected them in series to see what you get, that is how you will learn, and you will find out what your meter can do or cannot do.

[budm]

Re: Sony KDL-65W850A Dead

BTW, do you have a bunch of regular diodes may be like 10 of them, you can connect them in series and start checking them from 1 diode only, then 2 in series, and so on to see what you meter will show.

[kevinm34232]

Re: Sony KDL-65W850A Dead

I cannot get it to light up, with 3V at 100mA or 6V.. I believe this is wired differently than the usual. What should the mA be at 6V?

[budm]

Re: Sony KDL-65W850A Dead

I usually limit to 50mA first, does not matter if you are ting dual LED (6V) or single (3V).
So NONE of the LED light up?
You are testing EACH LED, right? not the LED strings.

[kevinm34232]

Re: Sony KDL-65W850A Dead

Nope and a few more test ones are out burnt out now.. Red to Cathode, Black to Anode reads 0.75V, so apply voltage same way correct??

[budm]

Re: Sony KDL-65W850A Dead

Nope and a few more test ones are out burnt out now.. Red to Cathode, Black to Anode reads 0.75V, so apply voltage same way correct??

As I explained that is the reading of the protection diode, you will have to revers your power supply leads to the LED to forward bias the LED, right now you forward biasing the protection diode, not the LED.

[budm]

Re: Sony KDL-65W850A Dead

BTW, ALL the LEDs are showing 0.7V?

[budm]

Re: Sony KDL-65W850A Dead

BTW, those LEDs have 4 terminals? I cannot tell from the pictures.

[kevinm34232]

Re: Sony KDL-65W850A Dead

OK so yes I mis read your post, I reversed the leads and increased voltage to 5V at 50mA and they finally light up! 6V makes them full brightness.

Even the ones that I had reversed and show open both ways with diode reading still light up..

So now what One of the LEDs I had messed up is much dimmer than the others, the rest are the same. Will the fact that they read open in diode mode affect them?

If they test good in diode mode does it mean the LED would be good too?

[budm]

Re: Sony KDL-65W850A Dead

So, of ALL the LEDs, only one is showing problem?

[budm]

Re: Sony KDL-65W850A Dead

The thread is getting long and I do not remember what you have found, I thought we were having the problem with the main board not sending the signals to the power supply board.

[kevinm34232]

Re: Sony KDL-65W850A Dead

Right, main board problem first, but I replaced main board and had new problem with TV turning on then back off with flashing standby LED, but not a blink code or anything described in the SM. It flashed from green to amber over and over again. But BL_ERR showed 6V.

BTW, I just found one bad LED in the first 65 strip I have been working on, the last one on the strip. Not including the one I messed up.
Possible to find compatible replacement LEDs? I have to look very close to see how many pins there are.

There are no strips available from Sony that I can find.

[budm]

Re: Sony KDL-65W850A Dead

OK, I see. I am not sure what the spec of the LED will be but we know it is dual LEDs in series but the current rating we do not know, may be some one can suggest what the replacement can be used.

[kevinm34232]

Re: Sony KDL-65W850A Dead

Can you explain dual LEDs in series, is this 2 LEDs in one component, or with the one next to it?

And what about the protection diode you were talking about, will this affect the function of the LED if it is showing open in diode mode both ways yet the LED still lights?

So far I found the one bad LED out of 2 strips, need to check the other 2 strips next.. And just FYI as I was dead wrong on this, the LED tests good in diode mode like the rest (0.75V and 0L), but does not light up.

It appears there are only 2 terminals on these.

If anyone knows how I can come up with a replacement, or some other way to bypass it I would greatly appreciate it as the longer the panel is apart, the less chance it has going back together...

[budm]

Re: Sony KDL-65W850A Dead

Dual LED such the one you have has two LEDs connected is series and mounted inside one package. As long as protection diode is not shorted out and the LEDs are still good, it should light up.
Not all white LED has protection diode.
See example here:
http://www.aliexpress.com/item/LG-LE...b-6aa0da9a1743

MODEL NAME : LEWWS73V15CZ00 7030 LED

Manufacturer : LG Innotek LED

Package Model:Loaded Quantity 3000PCS Per Reel

Forward Current (IF ): 140mA

Pulse Forward Curren t1 (IFp): 260mA

Reverse Current (IR):uA

Reverse Voltage (VR): 0.6-1.2V (5mA)

Power Dissipation (PD): 980mW

Operatin Tgemperature (Topr): -30 - +85 °C

Storage Temperature (Tstg): -40 - +100 °C

Soldering Temperature (Tsld): Reflow Soldering:260 °C
for 10secs

Hand Soldering:350 °C

for 3secs

Junctio Tnemperature (Tj ): 110°C

Forward Voltage (VF): 5.8-7.0V(93mA)

Luminous Flux (LM): -lm (93mA)
Luminous Intensity ( IV ) : 15-26cd (93mA)

Wavelength (nm) : -nm mA

CIE : x=0.2596 y=0.2341 (93mA)

Color Correlated Temperature (CCT): 8500-30000K

CRI : 80°

Viewing angle : 120°

Lead Frame Type LED Package: 7.0x3.0x0.8 mm LxWxH d=6.0mm

[kevinm34232]

Re: Sony KDL-65W850A Dead

Bud is this LED an example of one like the one I'm working with? Dual LED requiring around 6V? If the dimensions are close I will give it a try..

[budm]

Re: Sony KDL-65W850A Dead

That is just an example, It is only rated at 140mA, most TV backlights use 200~400mA rating.

[kevinm34232]

Re: Sony KDL-65W850A Dead

Man, the Aliexpress search is horrible?? Or is it just me???

[Diah]

Re: Sony KDL-65W850A Dead

yours LED on strip are 7020 edge 6 Volts, you can buy them from here Not tested... http://de.aliexpress.com/item/100pcs...327485437.html


or Tested just use 7030 6V 160mA , its little wide but same long .. you can buy them from here

http://www.aliexpress.com/item/100PC...445357361.html

[kevinm34232]

Re: Sony KDL-65W850A Dead

How do you know the size, I measured around 5mmx2mm