dboy
New User
Oct 10, 2016, 10:39 AM
Post #1 of 1
(1459 views)
Shortcut
|
|
Plasma TV problem - Help to understand findings
|
Can't Post
|
|
Summary: No picture on the screen, clicking noise from power supply, no visual condensator leak or swell. Clicking remains after disconnecting Y and X boards.
When measuring the stand by voltage the TV starts and the picture turns on.
What is wrong, Power stabilization or the main board?
Details:
I have a Samsung plasma, PS59D555C1KXXE with no picture.
The LED indicating standby power lights up and it seems to be waiting in stand by mode. However, when pressing "on" on the remote the LED blinks and a relay clicks on/off every 5 seconds or so with no image appearing on the screen.
I disconnected mains, removed the back panel, disconnected the Y and X boards, reconnected mains. The clicking sound is still there.
If I disconnect the main board board with the tuner/HDMI connectors etc, the clicking does not start.
The sound comes from one or both of two solid state relays (I think) mounted next to each other on the bottom left of the power supply board.
This could indicate a broken Main board, but since I need to press the "on" on the remote, it could also indicate that some logic signal is needed to be sent to the power supply.
I reconnected the Y and X board, the main board and logic board. Started the TV and measured the stand by voltage to rule out problems with condensators and power correction. The STB should be 5.1 V, was 5.3 V, but when I started to measure the STB voltage the clicking stopped and the TV booted and showed the start up image. When I removed the multimeter pin from the STB pin the image disappeared and the clicking started.
So, placing the multimeter in parallell to the STB output "fixed" the problem. What does this mean?
Is it most likely the power supply or the main board?
Should I remove and change power transistors and condensators allthough they "look fine"?
System: Hungarian made set from March 2011.
Power supply: BN44-00445A
|
FORUM
SEARCH
WHO'S 
LOG 
RULES