Hello,
I'm looking at a Samsung model ue55nu7096u that I've only ever seen in a non-working condition, i.e. I don't know if the failure was progressive or instant.
Symptoms
No backlight at all — LCD and logic board are working normally. Resetting all settings and installing system updates has no effect.
I tried reseating the connectors between PS and logic board, and PS and panel. No difference there.
I could not find a service manual.
Measurements when powered on
Bulk cap: 388 V. Stable.
PS panel/LED connector:
Pins [1,2,3,4]+ are all connected with each other on the PS board.
Pins 1-, 2- are likewise connected on the board.
Pins 3-, 4- are connected on the board.
Positive pins measure ~237 V, relative the negative pins. Stable.
Total power draw about 23 W, compared with 12 W when unplugging the panel connector from PS, and 3 W in standby.
Goal
Determining with high probability whether the cause is a faulty LED strip before attempting the dreaded task of lifting the panel off. I imagine first having to acquire a pair of suction cups to do that safely anyway, not to mention replacement LEDs if there are any to be found.
Questions
1. Is there anything weird with the measurements? On the PS board I can read '55": 109 V ↑' which I'm not sure about... It's the 55" model.
2a. Are all the LEDs in series? If so, I assume it's probable enough that they're at fault, so that I can confidently order replacements.
2b. If not all in series, is it still likely that multiple strips have died?
3. Having a bit of trouble finding listings for a replacement — only finding LEDs for similarly numbered models like UE55NU7300, UE55NU7100, UE55NU7105 — but I'll cross that bridge when I get to it I guess.
Background
I do repairs at a hobbyist level for fun. So far, every repair I've received guidance for on this forum has been successful (1 x PSU, 1 x CCFL monitor, 1 x amplifier). Thanks!
I'm looking at a Samsung model ue55nu7096u that I've only ever seen in a non-working condition, i.e. I don't know if the failure was progressive or instant.
Symptoms
No backlight at all — LCD and logic board are working normally. Resetting all settings and installing system updates has no effect.
I tried reseating the connectors between PS and logic board, and PS and panel. No difference there.
I could not find a service manual.
Measurements when powered on
Bulk cap: 388 V. Stable.
PS panel/LED connector:
Pins [1,2,3,4]+ are all connected with each other on the PS board.
Pins 1-, 2- are likewise connected on the board.
Pins 3-, 4- are connected on the board.
Positive pins measure ~237 V, relative the negative pins. Stable.
Total power draw about 23 W, compared with 12 W when unplugging the panel connector from PS, and 3 W in standby.
Goal
Determining with high probability whether the cause is a faulty LED strip before attempting the dreaded task of lifting the panel off. I imagine first having to acquire a pair of suction cups to do that safely anyway, not to mention replacement LEDs if there are any to be found.
Questions
1. Is there anything weird with the measurements? On the PS board I can read '55": 109 V ↑' which I'm not sure about... It's the 55" model.
2a. Are all the LEDs in series? If so, I assume it's probable enough that they're at fault, so that I can confidently order replacements.
2b. If not all in series, is it still likely that multiple strips have died?
3. Having a bit of trouble finding listings for a replacement — only finding LEDs for similarly numbered models like UE55NU7300, UE55NU7100, UE55NU7105 — but I'll cross that bridge when I get to it I guess.
Background
I do repairs at a hobbyist level for fun. So far, every repair I've received guidance for on this forum has been successful (1 x PSU, 1 x CCFL monitor, 1 x amplifier). Thanks!
Attached Files
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