Sony KDL-46ex700 led replacement still same issue

[labello]

I'm referring to the post #7 when you dismounted the double-double diodes on heatsink...
each one is a two diode with common cathode..

Hi i measured both and i have 17v and rapidly dropped it on 0.3

[Davi.p]

But the measurements made on the first post, on the led outputs, were also dropping rapidly?

[labello]

But the measurements made on the first post, on the led outputs, were also dropping rapidly?

Honestly I don't remember, anyway now it's taken the measurements with wire of the led inside of the board and without, nothing changed 🤔 very strange

[Davi.p]

so the voltage disappears or not in few seconds? Now i'm traveling in metro, at home i have a look at the board..

[labello]

so the voltage disappears or not in few seconds? Now i'm traveling in metro, at home i have a look at the board..

Yes it disappear rapidly, so I decided to take those off again and giving testing and both are okay, but then I look around and with a pen drive I discovered another mess look all of legs are moving so I cleaned and resolder those but one can't soldering because who touch this board long time ago doing bad work with soldering. My god it's a nightmare 😫

[Davi.p]

I see you already soldered the faulty joints, so did it changed something?

[labello]

I see you already soldered the faulty joints, so did it changed something?

Without this one, can i attach wire on it and soldering somewhere? Thanks no yet, im on break lunch

[Davi.p]

I see the top pins are normally unconnected, them are soldered only for anchorage

[labello]

I see the top pins are normally unconnected, them are soldered only for anchorage

Hey bro finally the tv work!! on primary side I have almost 800v (both capacitor) and 3.3 standby back also! But if I move the tv ( tv live mode) after about 5 seconds it turning off and no indicated of red light just black out , and doesn't want to start on again, i want to test it on hdmi output and we'll see may the problem is on tuner board itself...

[Davi.p]

Ma dai!? Wow! You are near the solution.. Clearly there are other solder joints to be renewed, but i'm ready to bet they're on the PS board again.. about the 800v it's a mistake certainly, there are no such tensions on the primary..

[labello]

Ma dai!? Wow! You are near the solution.. Clearly there are other solder joints to be renewed, but i'm ready to bet they're on the PS board again.. about the 800v it's a mistake certainly, there are no such tensions on the primary..

Ho cantato vittoria troppo presto!!😔😔😔 Again no power primary 320v and one of this diode goes up about 320v and goes down close to 0 the other one maximum 50 v and then goes down 0.. Dammed i lost my free time weekend with this tv🤬🤬
I know what you think but im not a manster to find problem 😂 thanks

[Davi.p]

these are the main switching power mosfets, not diodes, it's completely useless to check voltage on these components and also risky, you have to check voltage first on the power diodes of the secondary.. if it is present, then the primary is ok..

[labello]

these are the main switching power mosfets, not diodes, it's completely useless to check voltage on these components and also risky, you have to check voltage first on the power diodes of the secondary.. if it is present, then the primary is ok..

Hello , first of all, thank you for your guidance second i don't have any power on the secondary side I checked all only in the pictures circled have 1.6 voltage the rest of them 0 voltage. Also the single diode 0 voltage.. so if I understand there's some protection that stop the primary to work right...?

[Davi.p]

The protection always makes a "tic-tic-tic" sound hearing close.. if no tic-tic then the fault is in the primary..

[labello]

The protection always makes a "tic-tic-tic" sound hearing close.. it no tic-tic then the fault is in the primary..

No there's no sound at all!! I just finished to check both bridge rectifier (smd and large) no fault is in there.. I'll keep going 🤪😂

[labello]

I took the board off the tv and check if I have standby voltage and magically i have it so I'm almost going crazy or I'm going to be stupid ,because if i place the power supply on tv I don't have 3v standby I don't understand that it's a nightmare 😔😫

[Davi.p]

OK, test the power board alone, connect a jumper between Power-On , tcon-On 12v and Standby 3.3V, check every output V possibly with dummy loads, a resistor on standby 3,3v and a car lamp on 12v.. then if good, connect back lights and jumper also BL_ON, check again voltages and if back lights turns on..

...now i watch Tennis.. Go Sinner!..

[labello]

OK, test the power board alone, connect a jumper between Power-On , tcon-On 12v and Standby 3.3V, check every output V possibly with dummy loads, a resistor on standby 3,3v and a car lamp on 12v.. then if good, connect back lights and jumper also BL_ON, check again voltages and if back lights turns on..

...now i watch Tennis.. Go Sinner!..

Tomorrow I'll check, i didn't watch tennis because of this stupid tv🤬 have a good evening and thanks for your help

[labello]

OK, test the power board alone, connect a jumper between Power-On , tcon-On 12v and Standby 3.3V, check every output V possibly with dummy loads, a resistor on standby 3,3v and a car lamp on 12v.. then if good, connect back lights and jumper also BL_ON, check again voltages and if back lights turns on..

...now i watch Tennis.. Go Sinner!..

Hello man, I just came at home I really tired today, anyway I wanna to tell you that during the break launch I find a very good schematic for this board did you want it? Due teste ragionano meglio... I'll see you tomorrow have a good evening and let me know i will post the schematic maybe it could help someone in the future right. What do you think about it?

[Davi.p]

First we need the tests said..