Samsung eu75nu8000 no picture after tape method

[PNI E.]

isopropyl alcohol only

Perfect I order

[Davi.p]

The input of the pmic might be 12v, but probably it have internal short so the 12v get low as 4,8v, but... it is not 100% clear with no schematic, comparing with a common stand alone tcon, the first to be fed is the pmic, it generates the vcore rail at least, for the tcon processor, here the tcon processor is integrated to the main SoC, but there are 2 separated chips on 1 substrate, so i think the tcon part of the SoC (or call it CPU, it's the same) can be at fault or its balls are completely rotten

[Takeatry]

I was about to put my tv in the box and put it on the shelf but decide to do a little more investigation. Then I also noticed this post. I did a closer inspection of the back side of my MB. In the area under the cpu chip there were what I thought were burn marks on what looked like a cap. As I looked closer I noticed the darker components are probably not caps. I did take the time to do some measurements on that actual caps in that area. I noticed 2 of them beeped on the continuity test both sides to ground and one did not. Measured the 3 larger ones. 2 of them were under 10 ohms in both directions . The other I believe normal resistance readings. Photo below. Hopefully I am not causing more confusion. I know these boards are not the same, but thought if there is something to this, there is an opportunity to check and see if PNI E. has a similar issue.

[PNI E.]

The input of the pmic might be 12v, but probably it have internal short so the 12v get low as 4,8v, but... it is not 100% clear with no schematic, comparing with a common stand alone tcon, the first to be fed is the pmic, it generates the vcore rail at least, for the tcon processor, here the tcon processor is integrated to the main SoC, but there are 2 separated chips on 1 substrate, so i think the tcon part of the SoC (or call it CPU, it's the same) can be at fault or its balls are completely rotten

I think I’m going to search a new main board hoping it s not also a panel problem, but I really don’t know honestly but I see if I can find a used main board. When I watch YouTube videos of people who fix electronic things it s always the capacitor hahaha, but I think the voltage I check on the board aren’t good, it s like the ic is not giving current to the other component,

[PNI E.]

I was about to put my tv in the box and put it on the shelf but decide to do a little more investigation. Then I also noticed this post. I did a closer inspection of the back side of my MB. In the area under the cpu chip there were what I thought were burn marks on what looked like a cap. As I looked closer I noticed the darker components are probably not caps. I did take the time to do some measurements on that actual caps in that area. I noticed 2 of them beeped on the continuity test both sides to ground and one did not. Measured the 3 larger ones. 2 of them were under 10 ohms in both directions . The other I believe normal resistance readings. Photo below. Hopefully I am not causing more confusion. I know these boards are not the same, but thought if there is something to this, there is an opportunity to check and see if PNI E. has a similar issue.

honestly im not an expert, but what I can say it maybe there is something in parallel to that capacitor that make the resistence lower. I checked all the capacitor on the main board, and someone have 9 - 10 ohm and the tester beep. This capacitor are 3 4 near the cpu on the left side of the cpu, but I think it was normal…I think for be in short u must have under 1 ohm…but I’m not an expert

[Diah]

I was about to put my tv in the box and put it on the shelf but decide to do a little more investigation. Then I also noticed this post. I did a closer inspection of the back side of my MB. In the area under the cpu chip there were what I thought were burn marks on what looked like a cap. As I looked closer I noticed the darker components are probably not caps. I did take the time to do some measurements on that actual caps in that area. I noticed 2 of them beeped on the continuity test both sides to ground and one did not. Measured the 3 larger ones. 2 of them were under 10 ohms in both directions . The other I believe normal resistance readings. Photo below. Hopefully I am not causing more confusion. I know these boards are not the same, but thought if there is something to this, there is an opportunity to check and see if PNI E. has a similar issue.

these caps are under the SoC... inside the SoC there are Many coil at each circuit and these caps installed our side on the Soc pins as filters

honestly im not an expert,

the spray you used not air... its liquid.. so it could left behind and making the short... this why need to wash the boards with alcohol only

[PNI E.]

these caps are under the SoC... inside the SoC there are Many coil at each circuit and these caps installed our side on the Soc pins as filters





the spray you used not air... its liquid.. so it could left behind and making the short... this why need to wash the boards with alcohol only

Yes I just order 1 lt from Amazon a couple of days and I have here thanks

[Davi.p]

Takeatry, 10 ohms are the normal, also less.. you must keep for a plausible short less than 1ohm, i do not see burn marks nor discoloration. Fabrizio remember my reccomendations about what board to choose.. don't waste the path until now..

[PNI E.]

hi guys im. back.....i bought a new mainboard, the code are the same also the date of fabbrication, now the tv start but no picture and only menu sound no tv sound. with the old motherboard i had no picture but sound but i should unplug one of the ldvs or the tv didnt start. now the tv start and stay on with both the ldsv plug, but no sound only sound when i touch menu....do u think it s the panel? or the mainboard i bought could have some fault?

[lotas]

The new motherboard could be for a different region and the sound standard is not suitable, is there no sound via hdmi either?

[PNI E.]

The new motherboard could be for a different region and the sound standard is not suitable, is there no sound via hdmi either?

i didnt try...and the panel? the tv now start with the 2 ldsv plug in the backlight is on, the tv didnt turn off but the panel stay black. do u think it s the panel broken?

[Davi.p]

For the tv channels sound it's obvious you cannot hear sound because different tv set location of origin means different sintonization of the channels, to find a valid channel you may try to select the channel+ button many and many times until you find a valid memory.
For the bad panel question, i'm much more puzzled now that finally after a 40 days period i received the replacement main board for my tv, that had the same symptom as yours, with the original MB i tried a cpu reflow and the image came back but with defective lines, now with this new board, i have image but same horizontal lines, the behavior of the seller is bit suspective, he first started with gentle manners and declared it taken from working tv cracked panel, when i said to him that i decided to keep the board with a long explanation of why, he cut short and disappeared. Nobody can know if he lies or not.. a good technician knows that a board from a working tv have more selling chances of a board from defective set.. and that's all for now, i will continue to investigate..

[PNI E.]

For the tv channels sound it's obvious you cannot hear sound because different tv set location of origin means different sintonization of the channels, to find a valid channel you may try to select the channel+ button many and many times until you find a valid memory.
For the bad panel question, i'm much more puzzled now that finally after a 40 days period i received the replacement main board for my tv, that had the same symptom as yours, with the original MB i tried a cpu reflow and the image came back but with defective lines, now with this new board, i have image but same horizontal lines, the behavior of the seller is bit suspective, he first started with gentle manners and declared it taken from working tv cracked panel, when i said to him that i decided to keep the board with a long explanation of why, he cut short and disappeared. Nobody can know if he lies or not.. a good technician knows that a board from a working tv have more selling chances of a board from defective set.. and that's all for now, i will continue to investigate..

thanks for your answer and your support, yes i think also that the mainboard i bought can have some problem...but we ll never know.... i mean maybe an expert can test but i really im lost now...because now the tv starts with both the ldvs so means the panel should be ok, but no more sounds, only menu sounds....before with the broken mainboard i must disconnect one of the ldvs,(was not important what ldsvs i unplug) and the tv with one ldsvs pulg in turn on and i had voice.... Maybe the mainboard that they sell me was not good...there is an other mainboard in europe...but honestly i give up, because all the sellers say the tv come from a tv with broken lcd but we cant be sure. thanks for all your help

[Davi.p]

If the second board comes from outside Italy then the sticker BN94 code must match, otherwise there can be a DVB-T2 only tuner, i don't know, here in Italy we haven't still passed to DVB-T2..
OK you give up, but it's a good idea to post a Subito / ebay listing and give it for free, unless you want to sell boards separately.. it's a shame otherwise..

[Davi.p]

More.. i suspect there is also a Mafia around TV boards.. so i'm subscribed to a saved search to buy a whole broken cracked TV, same / similar model..

[bohaboha]

i didnt try...and the panel? the tv now start with the 2 ldsv plug in the backlight is on, the tv didnt turn off but the panel stay black. do u think it s the panel broken?

Hi did you find a solution for your new Mainboard?

[PNI E.]

Hi did you find a solution for your new Mainboard?

i just gift the tv, i gave up on try, im sorry

[nomoresonys]

You might want to keep that repair man, he seems pretty honest. He gave you the best advice for this samsung model.