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Old 10-08-2021, 06:42 AM   #1
bstewara
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Join Date: Jun 2019
City & State: Spring Hill Florida
My Country: USA
Line Voltage: 120VAC
I'm a: Knowledge Seeker
Posts: 34
Default Samsung un49mu7000f dead no power

Hi.
Iím working on a Samsung UN49MU7000F that has no standby LED indicator.
No POWER
The power supply board is part number BN44-00876A
The main board number is BN94-12399A
I am stuck.
I have replaced both pwr supply and main board with no changes.
Here are some of the readings from my multi meter on various locations on my power supply

MAIN BOARD UNPLUGGED. BACK LIGHTS ON PLUG CNL802 85 volts
Backlights are all illuminated and in operating range.

MB PLUG CNM803. - UNPLUGGED

PIN 1 FAN COUNT - Open
PIN 2 ANA DIM - Open
PIN 3 A13V. - 12.89
PIN 4 OD ON/OFF - 2.163
PIN 5 A13V. - 12.89
PIN 6 PWM BLU - 2.106
PIN 7 A13V - 12.89
PIN 8 PWR ON - 1.665
PIN 9 A13V - 12.89
PIN 10 GND- GND
PIN 11 GND -GND
PIN 12 GND-GND
STB VOLTAGE TEST POINT ON BOARD 12.89. (Should read 7.5 and 11.8)

With MB PLUGGED IN. NO BACKLIGHTS.

MB PLUGGED IN CNM803 READINGS

Pin 1 FAN COUNT open
Pin 2 ANS DIM open
Pin 3 A13V 9.03
Pin 4 OD ON/OFF open
Pin 5 A13V 9.03
Pin 6 PWM BLU 34 ohms
Pin 7 A13V 9.03
Pin 8 PWR ON open
Pin 9 A13V 9.03
Pin 10 GND. gnd
Pin 11 GND gnd
Pin 12 GND gnd
STB VOLTAGE AT TEST POINT 9.03

Iím just not sure of what voltages should be reading at CNM803.
Any help would be appreciated!
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