Re: 50PG25 plasma screen garbage (pictures)
The signal is chained from each IC . This is what I wanted to know.
Thanks Tom
Cailloux
Member
Last Activity: 08-27-2023, 11:51 AM
Joined: 02-02-2012
Location: Quebec
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50PG25 plasma screen garbage (pictures)
Hi, I need your opinion. LG Plasma TV 50PG25.
Two y-buffer in place as pictured. With no input signal, the result show on second picture. On the screen, a missing part of the top and the balance of garbage.
If I remove the upper buffer, I get down half a screen, a raster low intensity, no missing horizontal lines. I know the upper buffer is defective, the chip on top is very warm.
Menu on screen show also garbage.
My question: Is the upper buffer is solely responsible for the garbage on the screen? and possibly another faulty board (y-sus, ctrl)?
Tha...Last edited by Cailloux; 12-27-2012, 07:14 PM. -
Re: Samsung plasma PN42C450 shut down
Hello, I have finally solved the problem, I did not replace any boards.
At first, I mentioned having installed two fans in the upper back panel, one left the other right.
It draws air from the inside to the outside to expel the heat.
I installed a third fan in the bottom left, near the Y-Sustain, it draws air from outside.
That's it, it works very well for over ten days, every night without problems. Three fans, 12 volt @ 150mA each.
Thank you for your support....Leave a comment:
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Re: Plasma 42V7 problem - please help!!!
Voltage readings are good, ripple also.
The scope or multimeter is poorly calibrated. Use a know good reference to check.
The majority of plasma that I repaired, the Y main is very hot more than the Z board. Very hot for the fingers. In your case, the picture switch on / off, your Y is less request, this is probably the reason it is colder than the Z. I install two fans on the rear panel, can help prolong the life of the TV....Leave a comment:
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Re: Plasma 42V7 problem - please help!!!
Some suggestion.
In the service manual, it says LED1 on the power supply, is it blinks when the picture is black?
Did you check the boards with a magnifying glass to detect cold solder?
Do you have a ESR tester (Equivalent Series Resistor) to check the capacitors?
Connect the oscilloscope on the power supply Vs, Va, 5V, etc. .. are they really stable when picture come in and out?Leave a comment:
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Re: Samsung plasma PN42C450 shut down
Thank you to Randteck, I tried the trick, it's a good test tool. I followed his procedure to eliminate the main board. After 1h35m the tv shutdown.
Now who is the ugly board. I think but am not sure, the Y main would it be responsible?, it gets very hot.Leave a comment:
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Re: Samsung plasma PN42C450 shut down
Ah! sorry. I removed the power supply, and re-inspected with a magnifying glass. No cold solder found. Resolder the power transistors to be sure. 50 minutes later the picture has disappeared again.Leave a comment:
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Re: Samsung plasma PN42C450 shut down
I removed the Y main, and re-inspected with a high magnifying glass.
Nothing found. Replaced the board, turn on TV, 45 minutes later the picture has disappeared.Leave a comment:
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Samsung plasma PN42C450 shut down
I have a Samsung plasma TV PN42C450B1D year 2010 with a strange problem. An outstanding picture. Cold start, after 20 minutes, the picture disappears, the sound is still present, it responds with the remote control (power on / off, volume, input changes).
I turn off tv then i turn on tv, the picture appears then disappears after 10 minutes. Vs and Va shut down, this is normal since Vs_on from control board goes low, but why?
I do not have the service manual.
With a picture, I checked every voltage, Vs, Va, Vscan, +5, +15, PS_on, Vs_on (3.3v), all normal.
...Last edited by Cailloux; 07-04-2012, 03:26 PM. -
Re: LG plasma 42PC1DA Half left screen
Fortunately I had a TV 42PC3D, plasma screen is the same as 42PC1DA. So I transferred all the boards on the other screen.
Leave a comment:
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Re: LG plasma 42PC1DA Half left screen
Problem solved. Faulty screen, right side (rear view), burn spot on all COF (chip on flexible cable).
I do not know the reason, the circuit XR is in good condition, nothing to suspect.Leave a comment:
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Re: Plasma Y-MAIN board LJ92-01200A
Finally, problem solved.
Previously I had bought another used Y buffer $50. It was defective, the seller would not refund my money. I have long questioned, about the Y-sus board.
I take a chance, I'm crossing my fingers. I recently bought another used low Y buffer (another $50), and replaced Schottky diode D5022 3A 200V.
TV repair, it cost me $300 ($50 purchase of the TV, a new set of Y buffer $150, two Y buffer used low $50 x 2 = $100, and two Schottky diode.
I added on the back cover two...Leave a comment:
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Re: LG plasma 42PC1DA Half left screen
I have already replaced X board, labeling XR for the left side.
ThanksLeave a comment:
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Re: LG plasma 42PC1DA Half left screen
Hello, on the front left side, half the screen in dim light, with red sparkling, but more in the center bottom. Sparkling also appears on the right side of the screen.
At the back of the TV, the XR board is on the right side....Leave a comment:
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LG plasma 42PC1DA Half left screen
Hello, I need your technical assistance.
I have a LG plasma TV 42PC1DA defective.
Symptom: No picture on the left side of the screen, right side picture perfect.
What I did, replaced the control board & the XR board.
Replaced the cables. Checked the DC supply, +5 V and Va on the XR board, correct voltage, checked fuses. Same problem.
Is it possible that the main board is faulty?
Thank you.... -
Re: Plasma Y-MAIN board LJ92-01200A
Sorry I do not know how to deleted this post.Last edited by Cailloux; 02-08-2012, 06:31 PM.Leave a comment:
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Re: Plasma Y-MAIN board LJ92-01200A
Hi Tom,
I tried with a Schottky diode 3A 200V on D5022.
I installed only the lower Y buffer.
The diode shorted again but this time the lower Y buffer also short.
Do you think the Y buffer was defective even though she had no short-circuit at the beginning?
Or is it possible that the bottom screen is defective??
Have a suggestion?...Leave a comment:
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Re: Plasma Y-MAIN board LJ92-01200A
In my research, I saw this suggestion in another forum. I do not think it is a zener on the board because it is indentifies D5022, not Z5022. It is connected from the anode to a transformer, and the cathode to a capacitor of 100UF-160v. Seems to be a circuit filter....Leave a comment:
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Re: Plasma Y-MAIN board LJ92-01200A
Hi Tom,
You're right, I'll get a Schottky diode, but I do not know the values of amperage and voltage.
What is strange is that the diode fail only with the lower Y buffer. She has no short circuit.
I'll keep you informed. Thank you.Leave a comment:
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Plasma Y-MAIN board LJ92-01200A
Hello, I need help to troubleshoot a Y-MAIN board LJ92-01200A (LJ41-02759A) at the component level.
Prima plasma TV model PH42T7.
Initially, I found the two Y buffers defective, on the Y main a short circuit mosfet Q5009 (One of these 7 transistors in parallel), and a diode short circuit D5022.
D5022 is indentifies F6 5L.
I bought two new Y buffers boards, LJ41-02761A / LJ41-02760A, Q5009 I removed, and installed a 1N4007 diode (1 amp) at D5022.
I have not replaced Q5009 for now.
I installed Y upper board, and the Y main.
Turn on TV for 10...
No activity results to display
Leave a comment: