Re: Samsung UE49KS7000SXXH - No standby light
Yes, you are right, sorry about that.. Thing is that after first failed attempt, i got discouraged, and leaved the tv unfixed. And after half a year i got interested to try again, and after some more research on youtube i fixed it. After half a year i forgot about this forum. Only after i got email that OTwisk was asking me something here few days ago i remembered.
Sorry again.
B0r1s
Member
Last Activity: 09-16-2023, 04:20 AM
Joined: 06-22-2022
Location: Belgrade
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Re: Samsung UE49KS7000SXXH - No standby light
Yes, one of the connections from big transformator in the centre of the board was broken i guess. I removed solder from all these connections and added new solder at these spots, and it's working after that. There is a video on youtube, some guy fixed his samsung tv with reflowing these spots but cant find it now.Leave a comment:
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Samsung UE49KS7000SXXH - fast clicking sound in standby mode
PSU - BN44-00878A
Symptoms:
The TV turned itself off, and I haven't been able to turn it back on. The standby voltage was unstable and lower than it should be.
A weak clicking sound was coming from the transformer.
Video with clicking sound:[url]https://www.youtube.com/watch?v=lAduhjNtqCA[/url]
Progress:
After the transformer, I measured four Schottky diodes. DM862C and DM864C diodes readings were 003 in both directions. After detaching them from the circuit and measuring them, DM864C was the shorted one. These Schottky diodes...Last edited by B0r1s; 01-17-2023, 05:05 PM. -
Re: Samsung TV UN55KS8000 dead - bad diode
Hi, i have the same problem like you had, but on mine board, third diode was shorted, i replaced all four diodes, but after tv was on for 10 minutes, diode went short again. Same diode that was bad before
Here is the thread with my problem - [url]https://www.badcaps.net/forum/showthread.php?t=107589[/url]
Is your tv still ok after you fixed it?Re: Samsung TV UN55KS8000 dead - bad...e was shorted,...Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
All 4 caps are on the shorted diode path, plus sign of caps are on that line.
What to test on it? Voltage or? I need to solder diode back before testing it with power on?...Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
So short can happen if 60+ voltage (SB560 is 60v) come to the cathode (-) of the diode?Last edited by B0r1s; 07-28-2022, 12:21 PM.Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
Image of the board.. if something is causing diode to get shorted, do we need to look before diode or after?
That diode and one next to it (second adn third diode) are connected to the transformer pin. I guess that in the middle is the transformer? Another two diodes are connected to the oppsoite transformer pin...Last edited by B0r1s; 07-28-2022, 11:00 AM.Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
I just took out diode from position where last diode was shorted, and this one is also shorted.. other diodes are ok just like before. It is a bit strange that i got shorted diode again in the same spot.
Resistors? Which ones? I only see one that is nex to heatsink....Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
Yes, several times, outaide of circuit and in after i put it.. i tried tv few times and tested diodes again. Everything was ok till tv shut down itself. I know what diode was shorted before, i will take out replaced diode in that place, i think that diode is shorted again.....Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
I just opened tv, and again two diodes are shorted (one of these two) just like before. So i guess something is causing that diode to fail? I get 0.0 reading on both ends. And standby voltage is unstable and around 4-5v just like before. In short everything is like when we started. Tried unhooking motherboard, same behavior, light comes for a second and go out.
What can be a culprit?
Also i noticed now, with bad diode, ticking noise is slower (pauses between ticks are longer) when voltage was good after i replaced...Last edited by B0r1s; 07-28-2022, 04:56 AM.Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
Yes i noticed ticking noise after i removed back cover for the first time..
I did have a bridge with the small solder spot, but i think i removed excess solder.. what are these solder spots that are placed around diodes, many small solder spots? They do not hold any components from the other side?
Also i forgot to mention. When i replaced diodes i checked standby voltage and reading were:
When in standby 9.55 (on board it says 7.5)
When tv is on 12.83 ( on board it says 11.8)
Maybe something...Last edited by B0r1s; 07-27-2022, 06:15 PM.Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
But i noticed again fast ticking noise while tv is in standby mode. When tv is on, ticking noise is not present. This noise can only be heard from very small distance, maybe 10 cm.. so i don't know if that noise was present before.....Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
I rechecked diodes after i finished, readings were ok, and i was careful about polarity. And i checked cables few times also.. i will check standby voltage and diodes again tomorrow....Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
Solder station arrived. Replaced all 4 diodes. Turned on tv without data cable, and picture showed. Tried few times..
After reattached back cover and data cable, I turned it again, and after few minutes same problem, tv turned itself off and no standby light.. It turned itself off while i was in plex app and it was loading plex content.
Tomorrow i will disassembly it again.Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
Sorry for delay. I ordered quicko t12-942 from china, and I'm waiting for it to arrive. In the meantime i bought electric desoldering pump and took out two diodes, and yes one is shorted.
On the diodes it is printed:
LT6 | 23
SB5 | 50
Searching trough google i figured out that this is sb 550 schottky diode. I only found sb 560 diodes to buy.
While testing sb 550 and sb 560 diodes out of circuit i get different readings in diode mode:
SB550: 0.350
SB560: 0.195...Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
Ok i rechecked these diodes with diode mode. I have these two multimeters at the moment, and measurements are different on each one. I don't know which one to trust.
Multimeter MT111:
DM862C - on each measurement multimeter is changing settings from diode mode to ohm resistance and i get values - 0 ohms.
DM864C - same like with DM862C
DM863C - red lead on anode, black on cathode - 0.284 / when i switch leads - 0.794
DM861C - same like with DM863C
DM851C, DM852C,...Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
I measured stby voltage with disconnected backlight socket like nomoresonys told me, and stby was still unstable.. i will try in few hours to test power board detached from tv frame with only power cable attached like you said so.....Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
I checked following diodes with 20K ohm settings.
4 big round ones:
DM862C - .004 and .004 both directions.
DM864C - .004 and .004 both directions.
DM863C - 1.679 in correct direction and 1 in opposite.
DM861C - 1.679 in correct direction and 1 in opposite.
DM851C, DM852C, DM853C:
negative lead on middle leg, positive on other legs: .484
positive lead on middle leg, negative on other legs: 1
Positive lead on first leg...Leave a comment:
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Re: Samsung UE49KS7000SXXH - No standby light
Just tried, same unstable stby voltage
Which diodes are output ones on board?...Leave a comment:
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Samsung UE49KS7000SXXH - No standby light
Hi, my tv turned itself off and since than i can't turn it on. I have no standby light.
I tried like i saw on few youtube videos to disconnect the cable that is coming from the main board and than to power on tv, to see if backlight will appear, it did appear but only for a second, and while power cable was attached I noticed small ticking sound from the middle of power board. Than i attached the main board cable again and ticking sound was still present. I guess sound is coming from transformer area, but not sure.
Then i measured stby voltage on the board, and it is...Last edited by B0r1s; 06-22-2022, 12:11 PM.
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