Sony KD 49X8307C

[nomoresonys]

is there a test/fix for this? Nomoresonys Snr 😁

I think without taking it off and checking the health in a tester, which is not an easy task. The other is process of elimination, which Diah is taking you thru. Testing you can try after that is check if you are getting the 3.5 and 12 volts from the powerboard thru to the mainboard, if those voltages are there you can remove the heatsink from the processor and test the little caps nearby for shorts, if none found then it's probably that damn eMMC that's bad.

[Donny2derby]

NO
if the fuse to chassis 0V mean mainboards didnt send signal t-con_on... so we need now to do this test

testing power boards and T-CON and panel as standalone
1- disconnect the sockets between Power boards and Mainboards ( from mainboards side )
2- disconnect the 2 LVDS cable between Mainboards and T-CON ( from T-CON side )
3- if you have 1K R use it in case you don't have.. you need to recheck the pins points bellow 3 time to be sure they are correct.

4- we connect

STBY3.3V ----1KR ---- to all together pins POWER_ON & BL_ON & TCON_ON then plug in wall check the screen if iz come on..... and check if there all Volts on sockets REG12V ( 12V) and on T-CON fuse 12V

Ok Diah. So we’re clear. What you wish me to do is link together Standby 3.3v pin with POWER ON, to BL-ON and TCON-ON. Through a 1kw resistor?

Then check the voltage on all 6 REG 12v pins and the T-Con fuse? Is that correct?

If so we will have to wait until I’m back at work next week when I have my solder station and 1k ohm resistors.

Thank you for your guidance and knowledge👍🏻

[Donny2derby]

Jesus Diah you aren’t making things easy for me are you! It’s a tight squeeze to get a resistor onto just the 3.3v Standby pin and then link over to the others.

[Diah]

Jesus Diah you aren’t making things easy for me are you! It’s a tight squeeze to get a resistor onto just the 3.3v Standby pin and then link over to the others.

its very easy,,
1- put the 1KR between STB & BL_ON... then make wire between BL_ON and power on... and another one between power_on and T-CON ON

[Donny2derby]

Haha it might be easy for you Diah but this is micro soldering and not something I’m used to. I have resistor between 3.3v and POWER ON at the minutes and I’m about to try and link over from POWER ON to BL-ON then to T-CON ON.

[Donny2derby]

Diah this is fucking ridiculous! There is less than a 1/4mm between each of these pins! I can’t even find wire gauge of this thickness! It is impossible to not bridge these pins! So frustrating!

Even the thickness of the lines you have drawn on the picture illustrates how difficult it is! I’m just making a mess of the board here!

[Donny2derby]

Ok Diah. I have done as you asked to the best of my abilities. Plugged the telly in and the screen doesn't come on. I still don't have 12v on T-con fuse.

Im also quite concerned that if I flip the power board over to test the 12v REG pins then one of the components on the board is going to short through the chassis.

And removing the board from the chassis will make it ungrounded and I won’t be able to test 12v REG surely?

[Donny2derby]

This is the board now. I know it doesn't look pretty but I have tested across all the pins and there is continuity across the pins you instructed me to link out but nothing is shorted across anything else.

[Donny2derby]

Ok Diah nothing in terms of 12v on T-con fuse, and no 12v on any 12v REG pins to chassis.

Where do I go next?

Thanks.

[Diah]

This is the board now. I know it doesn't look pretty but I have tested across all the pins and there is continuity across the pins you instructed me to link out but nothing is shorted across anything else.

OHHH my GOD... you are of sure heavy metal technician ... STOP Please and clean yours work as much you can no any short between pins... and put every things back as original... try to find Mainboards. or rework BGA on yours.... heat GUN , BGA station.... if nothings then go head to yours Kitchen LOL....

[nomoresonys]

Jesus Diah you aren’t making things easy for me are you! It’s a tight squeeze to get a resistor onto just the 3.3v Standby pin and then link over to the others.

There's the no solder method, sometimes I jumper thru the end of the cable, as in the end that is removed from the mainboard, by carefully tracing the wire back to the other end of the cable. Some use a jig they rig up from various old cables they have collected, with that first method you need to make sure your getting a good connection, with soldering you know the connection is good: https://www.youtube.com/watch?v=vadiCOh_LzY

[nomoresonys]

Best practice is use resistors, but if you are very careful and do the jump correctly, you can do it without resistors.

[Donny2derby]

OHHH my GOD... you are of sure heavy metal technician ... STOP Please and clean yours work as much you can no any short between pins... and put every things back as original... try to find Mainboards. or rework BGA on yours.... heat GUN , BGA station.... if nothings then go head to yours Kitchen LOL....

Haha I appreciate it doesn’t look great Diah and I will invest in some proper micro soldering equipment but I can assure that the pins you asked me to link are linked but nothing is bridged anywhere else.

I will however do as nomoresonys suggest and try to use resistors as opposed to copper wire later.

But I still wasn’t getting any 12v anywhere you asked me to test to so what is next test after this?

[Donny2derby]

I have ordered some finer soldering iron tips Diah so will begin the process of attempting to tidy up my work when they arrive.

During testing last night though I did come across various components that were shorted. Diodes giving a diode junction when tested one way and a short when tested the other way. Would you expect this when the pins you asked me to link are connected?

[nomoresonys]

Make sure you are testing the diodes correctly, check them in circuit, if they read as expected they are probably ok, if you get a strange reading and your not sure if it's just another component in the curcuit like a resistor across, just lift a leg of diode and recheck: https://www.youtube.com/watch?v=-eQSIEJ4Rqg

[Donny2derby]

Make sure you are testing the diodes correctly, check them in circuit, if they read as expected they are probably ok, if you get a strange reading and your not sure if it's just another component in the curcuit like a resistor across, just lift a leg of diode and recheck: https://www.youtube.com/watch?v=-eQSIEJ4Rqg

Thanks mate. I’m pretty sure they are giving bad readings but will lift a leg out of them later and recheck just to be on safe side. Diah Nomoresonys Edwards. Has a certain ring to it😁

[Diah]

Haha I appreciate it doesn’t look great Diah and I will invest in some proper micro soldering equipment but I can assure that the pins you asked me to link are linked but nothing is bridged anywhere else.

I will however do as nomoresonys suggest and try to use resistors as opposed to copper wire later.

But I still wasn’t getting any 12v anywhere you asked me to test to so what is next test after this?

where you put the DM black probe?? yours boards are out of circuit.. so the chassis should be at the COLD area.chassis

[Donny2derby]

Ok Diah & nomoresonys, if you want to move yourselves further up into contention then let’s get moving with some solid technical advice! A fixed telly is a contribution to the nappie (diaper) and milk formula fund!

[Donny2derby]

where you put the DM black probe?? yours boards are out of circuit.. so the chassis should be at the COLD area.chassis

Ahhh I see Diah. Ok I removed the CN201 plug and tested onto the 12v REG pins onto the chassis of the tv. I will try again later with the plug reinstated and test onto cold side of board GND?

[Diah]

Ok Diah & nomoresonys, if you want to move yourselves further up into contention then let's get moving with some solid technical advice! A fixed telly is a contribution to the nappie (diaper) and milk formula fund!

hahahah,,,, thats cool... nomoresonys on the last list