Samsung UN55ES7003 has blown fuse on TCON and short to ground.

[triplefour]

Samsung UN55ES7003
made house call.
red power led comes on, blinks twice, no display, no backlight, relay clicks, repeat.
psu has self test feature.
disconnected from mainboard.
determined PSU ok BL ok.
suspect mainboard.
disconnecting tcon has no change on operation.
markings on mainboard:

BN97-06531P 0151
BN94-06123R

found and ordered replacement on ebay https://www.ebay.com/itm/394077328633
for 54$

second house call:
with replacement mainboard, tv turns on, has sound, but no backlight and no picture.
when tcon is disconnected, tv has sound, and only the bottom 1/4th of the screen appears to be lit.
i believe this is an edge lit screen.
never seen that before. i was expecting the whole screen to be lit.
maybe its some kind of error code to tell you the tcon is disconnected?
when i do backlight test by disconnecting mainboard, the whole screen is lit.
inspected TCON more closely (should have done on first house call) and found that 12v is coming into the fuse,
but not out the other side. fuse is blown!
further inspection reveals there is a short to ground somewhere in that area of the board.
the short to ground seems only in that area and affects 3 capacitors on the backside of the board as well.
i removed 3 small surface mount ceramic capacitors on the front and lifted the leg of diode D100 but the short is still there.
i am thinking of removing the IC that is in that area as it also shows shorted and could be the source of it.
if that doesnt work i can continue shotgunning parts off the board, or actually learn how to do voltage injection.

[CapLeaker]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

If you do use voltage injection, just remember that you do not inject more voltage than that voltage rail you in jest into can handle. So for example a 3.3V rail, make sure you don’t exceed 3.3V. The amps depends on the circuit, maybe start with 1A. If you can’t find the problem after 3 mins, put 9x% IPA on the board. The faulty part will make the alcohol bubble off.

[triplefour]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

i have a power supply i was going to try to use for voltage injection but something is wrong with it and i cant set the amps....thinking of buying a tool specifically for it. i guess in this case, 12v would be required.

[nomoresonys]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

Samsung UN55ES7003
made house call.
red power led comes on, blinks twice, no display, no backlight, relay clicks, repeat.
psu has self test feature.
disconnected from mainboard.
determined PSU ok BL ok.
suspect mainboard.
disconnecting tcon has no change on operation.
markings on mainboard:

BN97-06531P 0151
BN94-06123R

found and ordered replacement on ebay https://www.ebay.com/itm/394077328633
for 54$

second house call:
with replacement mainboard, tv turns on, has sound, but no backlight and no picture.
when tcon is disconnected, tv has sound, and only the bottom 1/4th of the screen appears to be lit.
i believe this is an edge lit screen.
never seen that before. i was expecting the whole screen to be lit.
maybe its some kind of error code to tell you the tcon is disconnected?
when i do backlight test by disconnecting mainboard, the whole screen is lit.
inspected TCON more closely (should have done on first house call) and found that 12v is coming into the fuse,
but not out the other side. fuse is blown!
further inspection reveals there is a short to ground somewhere in that area of the board.
the short to ground seems only in that area and affects 3 capacitors on the backside of the board as well.
i removed 3 small surface mount ceramic capacitors on the front and lifted the leg of diode D100 but the short is still there.
i am thinking of removing the IC that is in that area as it also shows shorted and could be the source of it.
if that doesnt work i can continue shotgunning parts off the board, or actually learn how to do voltage injection.

good logic, it usually is the ic next to the caps that are reading short that is bad.

[diif]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

12v is the main voltage rail, so you would only inject 1v, do you have a hot air station ?

[triplefour]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

they dont want to wait for me to poke around at the component level. the replacement tcon will be ordered for 35$ lets hope that the problem ends there! I still need to learn voltage injection and general shorted component finding though, so i plan to keep the defective TCON and see if i can learn something from attempting the repair.

and to answer diif's question i do have a hot air station. its nothing special some aouye 3 in one soldering iron, hot air, and preheater

\

[diif]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

How is waiting for something to arrive by post quicker than turning on your hot air and removing those few components or soldering a couple of wires and turning on your power supply ?
If you aren't confident in removing those components with your hot air, spend time with scrap boards taking various components off and putting them back on.

[nomoresonys]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

"i am thinking of removing the IC that is in that area as it also shows shorted and could be the source of it": so did you try this?

[thommyX]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

Look CD12 33uF 25V and QD1 FDC658AP

Greetings Thomas

[triplefour]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

"i am thinking of removing the IC that is in that area as it also shows shorted and could be the source of it": so did you try this?

I finally got around to it and sure enough, the ic is shorted across and with the ic out the shorts have disappeared. I should have attacked the ic first! Now I have these 3 mlccs to deal with...it raises another question. How do I know what spec these mlccs are supposed to be when they aren't marked? How can I get a correct replacement if I've damaged them?
The ic is labeled 4435D so probably fairly easy to look that up and find another one but now I'm worried about the mlccs more than anything else!

[petehall347]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

[triplefour]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

Look CD12 33uF 25V and QD1 FDC658AP

Greetings Thomas

Cd12 seems fine but qd1 pins 1,2,5,6 are shorted to each other and the part in cd1 is shorted to ground on both sides. Only pin 4 of qd1 is shorted to ground. Probably is the ground pin. Not sure what this ic should look like but 4 pins shorted to each other seems suspicious...or maybe not...the traces on the board do look like they are all connected there...pin 3 looks like it doesn't go anywhere...
CD52 and CD53 are shorted to ground on both sides as well...but all the other components in the area are either not shorted to ground at all or only on one side which seems normal

Edit: I noticed BD200 which is between the fuse and the source pins of Q201 is shorted...but what is BD200 in the first place? Don't know all the codes.

[nomoresonys]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

I finally got around to it and sure enough, the ic is shorted across and with the ic out the shorts have disappeared. I should have attacked the ic first! Now I have these 3 mlccs to deal with...it raises another question. How do I know what spec these mlccs are supposed to be when they aren't marked? How can I get a correct replacement if I've damaged them?
The ic is labeled 4435D so probably fairly easy to look that up and find another one but now I'm worried about the mlccs more than anything else!

very good question, not sure how standardized they actually are, a little info there: https://passive-components.eu/mlcc-c...rds-explained/

[triplefour]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

Thanks. I read it. I know more now than I did. But not much more. Just that the markings on mlccs refer to the width and length of the case....in inches!!! But this info is not accompanied by a capacitance rating. Apparently this rating comes from the height...which is not marked. And in my case none of the mlccs in question are marked anyway...

But I had another question about marking codes. The code bd200...what could that stand for? I found this incomplete article that sounds like it wants to have the answer but just falls short
https://www.ultralibrarian.com/2021/...es-to-know-ulc

And what does the CDXXX marking mean? They seem to be caps but what does the D stand for? Decoupling?

[R_J]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

The D (cDxx) is likely just that area of the circuit, just like the other side of the board has C (cCxx) and rCxx qCx etc.
The bd200 is just a ferrite Bead (it will check as a short)
CD52 and CD53 are likely 1µf/16v

[triplefour]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

The D (cDxx) is likely just that area of the circuit, just like the other side of the board has C (cCxx) and rCxx qCx etc.
The bd200 is just a ferrite Bead (it will check as a short)
CD52 and CD53 are likely 1µf/16v

Thank you for clarifying all that. I was reading another post and saw something about a ferrite bead and was wondering if that could be it. What is the purpose of the ferrite bead?

How do you know what those unmarked mlccs might be?
CD52 CD53 and cd01 are all reading short to ground on both ends. Thats a problem for sure. I better look the data sheet for that ic right there and see if the readings I get make sense for it.

[nomoresonys]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

might only be one shorted, maybe remove one and test it out of circuit and test the others still in circuit, see if they still read short.

[triplefour]

Re: Samsung UN55ES7003 has blown fuse on TCON and short to ground.

this tv got fixed by replacing the Mainboard and the TCON ... bad failure somehow took out both. i still have the bad MB and bad TCON which i may continue to investigate/repair