Re: Samsung Plasma PS50C7790 with black screen but sound
no, with the posted setting for the Y-sustain I only got a litte jump from the horizontal line of the oszi when I start up the TV from standby. No wave or rectangle impulse at all. Can I try a different setting at the scope?
On the X-Sustain its compareable, but the jump is 1 division up. After a cold start, the jump goes fast to 3/5ths of the next division and then goes slow to reach the end of this division. But also no wave or increasing line on the display of the scope: just the whole line goes up and down...
Axesh
Member
Last Activity: 06-19-2013, 07:13 AM
Joined: 06-06-2013
Location: BW
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Re: Samsung Plasma PS50C7790 with black screen but sound
here you go......Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
with the original setting from you and the x1 probe with the hook (the other one doesnt work with the calibrator) the flat line jumps up a little bit (1/10th of a div) with clicking of the relais by start and shut down of the TV.
When i measure that with the scope meter, it displays a voltage of 0.39 on start up and an -0.39 on shut downLast edited by Axesh; 06-17-2013, 03:49 PM.Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
Edit...
with the calibrator I got something like this (the dottet line is a complete line, like the bottom line):
----_____-----_____
but what should i have to set on the trigger selector? ac, dc, hf, lf or line?
or does it matter?Last edited by Axesh; 06-17-2013, 03:26 PM.Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
do you mean AC with ~ for the Trigger Selector?
I got a probe with a hook, but its only a x1 probe.
I put it in Channel 1, but still no peaks on the scope... :-(
Is there an easy setup to verify that the scope is working correctly?Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
everythings set, except "Set TRIG to TV:H and DC"
I put the trigger selector to DC, but theres no TV:H...
What do you mean with "turn CAL arrow so it locks in the CAL position"
Is that the furthermost left position, on 9 o'clock?, that the only position where the knob is "locking"
My 10x probe doesnt have a hook, only a thin point.
So the black one you described is my one with the crocodile clamp?
But with this setting, a doesnt get a peak...Last edited by Axesh; 06-17-2013, 02:41 PM.Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
yep, I got one of these 1/10x probes, and here's the picture of the Y-Buffer Board...Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
so, do you have any advice what to measure on my TV?
Please keep in mind that I'm not familiar with that type of equipment... :-oLeave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
Hei Tom,
do you got some time to check the specs of the other scope?
Is it helpful for our test?
Thanks in advance...Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
Hi Tom,
no, I don't have a manual for that, and even didn't find one on the internet. But now I got another scope: HAMEG HM203-4, which is specified for 500V DC and peak AC. Can we work with that?
I attached a screenshot from the manual, which you can find [URL="http://www.hameg.com/downloads/man/HM203-4_english.pdf"]here[/URL].Re: Samsung Plasma PS50C7790 with black screen but sound
Hi Tom,
no, I don't have a manual for that, and even didn't find one on...Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
Hi Tom,
the scope and 10x probe is ready for testing...
Here's a picture of the scope.
Its a Createc SC 01, with only max. input voltage 220 VDC/VAC
Does this also fit?
Please give me a "call" when you have some time to get me through this...
...
Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
according to this video ([url]http://www.youtube.com/watch?v=JjrwTZC5nVg[/url]), the fault could be possibly be located in Y-Main, Y-Buffer or X-Main board, because the LED on the logic board is blinking in a 5s rythm (5s on, 2s off, ...). PSON behaves normal, Standby is always on 5v, only VSON is not like it should be. But according to the video, the logic board should be okay, because VSON gets up to 3.3v for a second, and did not always stay on 0v.
So, what I have to set up to test these boards with the scope?...Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
ok, I will try to get one tomorrow... *thumpsup* :-)
I just checked the VSCAN and VE voltage:
VSCAN is also decreasing from the normal -195v to 0v
and VE is decreasing from the normal 89v to 14.8v
Damn... :-(Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
i can get one, thats no problem, but I'm not familiar with an oscilloscope. So it would possibly be a challenge to test the boards with your advice... :-o
Or what do you think?
My understanding is now: SMPS is not the reason
The logic board detects a fault on start up, and in this case it shuts down Vs to 15v and Va to 0v.
Each of the connected boards could be the reason for the fault, including the logic board.
Am I right?, or whats your conclusion?Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
your right, VSON jumps shortly after start up to ~3,3v for a second, then goes down to 0v
Any chance to identify the fault that the logic board is detecting?Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
I measured the voltage on the connector pins on the SMPS:
VSON is always on 0v ("standby" and "on")
PSON (standby) is 3.3v
PSON (on) is 0.2vLeave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
any advice from the experts on this issue?
Can I measure anything else to determine the faulty board?
Thanks in advance.Leave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
yes, same decreasing voltage on the fuse you highlighted for me.
From about 55 to nearly 0, on both ends. It stops a 0.1v after ~40 secondsLeave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
no difference on this capacitor with or without the highlighted connector:
decreasing voltage from ~55 to nearly 0 volts in about 30-40 secondsLeave a comment:
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Re: Samsung Plasma PS50C7790 with black screen but sound
damn it. So whats wrong with it?
here the test with the battery..., with the same setting I used for the measurments above...Last edited by Axesh; 06-09-2013, 03:26 PM.Leave a comment:
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