Re: LG 50PC3D with flickering display
Thank you very much for your help. I will likely just retire this TV.
tictac
Member
Last Activity: 03-04-2016, 05:23 PM
Joined: 11-03-2014
Location: London, ON
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LG 50PC3D with flickering display
I have an old 50" plasma, LG 50PC3D. The symptoms are: sound is OK but the screen flickers several times per second... white, black, white, black, etc.
[B]So far I have found the following:[/B]
- Fan works
- no ticking sounds from any boards
- no visibly pregnant caps
- 5V is at 4.98 VDC
- Vs is at 197 VDC
- Va is at 59.7 VDC
- ZSUS heat sinks are both warm
- Top YSUS heat sink is cold
- Bottom YSUS heat sink is warm
I don't wish to spend much time or money on this TV as it is a 10-year old model.... -
Re: Sony TV, KDL-55EX621, white/grey screen with lines
Does that mean the boards are still good?...Leave a comment:
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Re: Sony TV, KDL-55EX621, white/grey screen with lines
Would this mean that the boards are still likely to be good?...Leave a comment:
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Sony TV, KDL-55EX621, white/grey screen with lines
I have this 55" Sony LCD with a video problem. The sound seems ok and the screen lights up but there is no picture data. The screen has large blocks of gray & white with darker horizontal bands scrolling upwards. See the photo below. If anyone has any suggestions, please let me know what other info is needed. Thank you in advance.... -
Re: LG, Model 47LG50, not coming ON
OK. It's been working fine for a number of hours now, so I believe we fixed it.
Thanks again. I'll leave a donation....Leave a comment:
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Re: LG, Model 47LG50, not coming ON
I re-soldered the components you suggested and the TV turned on as normal. Both, picture and sound, are good. I will leave it on to test run for 4-5 hours just to be sure that was the problem. Thank you for your advice and time.Leave a comment:
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Re: LG, Model 47LG50, not coming ON
With the TV plugged in and turned OFF, VCC-pin12 is at 2.69V. With the TV turned ON, VCC-pin12 is at 14.32V. These are measured with pin 10 as the reference.
[U]A new observation:[/U] Just after measuring these voltages, the back lights came on for about 15-20 seconds and then went off again. I had no time to measure any other voltages while the lights were ON. I tapped the power supply everywhere, thinking there may be a bad connection some place, but I couldn't get the back lights to come on again.
...Leave a comment:
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Re: LG, Model 47LG50, not coming ON
I will get good closeup pictures in the daylight tomorrow morning.
The IC part numbers are on the attached picture....Leave a comment:
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Re: LG, Model 47LG50, not coming ON
Here they are. I may be able to get better closeups tomorrow in the daylight if you need....Leave a comment:
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Re: LG, Model 47LG50, not coming ON
There are a number of dual diodes with their cathodes connected to large heat sinks. If I measure the anodes, with ground as a reference, should I be getting AC or pulsating DC?Leave a comment:
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Re: LG, Model 47LG50, not coming ON
BudM,
I have posted the voltage readings. When you get time, could you please let me know what I could check next. Thank you....Leave a comment:
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Re: LG, Model 47LG50, not coming ON
Budm,
The voltage readings in the previous post are poorly formatted. On each line the connector label is followed by a space and then the DC Voltage. When you get a chance, could you please give me an idea of what to check next.
Thank you.Leave a comment:
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Re: LG, Model 47LG50, not coming ON
Previously, I measured the 122 VDC directly on the PLUS & MINUS terminals of a bridge rectifier. Today, I measured the two large caps near the bridge rectifier and they were 384 VDC each. Following are the DC voltages on the 3 connectors on the PS board as you requested.
P201 (to main board)
LABEL DC Voltage
16.5 0
GND 0
12V 0.01
GND 0
5V 5.11
5V 5.11
GND 0
GND 0
ACD 0
ON/OFF 2.8
PMW-DIM 1.16
N.C. 0
...Leave a comment:
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LG, Model 47LG50, not coming ON
[B]SYMPTOMS:[/B] At standby the front LED is solid red. When turned ON, it flashes brighter red twice, then goes out. From the inside of the TV, I can see the light change to blue but it is barely visible on the front of the TV. There is no picture and no sound.
[B]TESTS DONE:[/B] Visually all the boards look normal, no burnt marks, no fat caps, no smoke. All cable connections were re-seated but made no difference.
With power unplugged, using "diode test" on a meter, all diodes and bridge rectifier tested OK. Although the Dual-Diode packages showed continuity... -
Re: Sharp LC60LE810 with Lamp Error
All the help is greatly appreciated, freakaftr8.
I followed your instructions and we have lights! Everything is now back together and I only had a few screws left over. We will spend the rest of Valentines Day watching a movie.Leave a comment:
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Re: Sharp LC60LE810 with Lamp Error
Well, I managed to get at the LEDs. So far I have tested one side by lighting up each LED with a meter on DIODE TEST. The one on the very bottom won't light. I will go ahead and test the remaining LEDs all the way around. It's tricky because they appear to have conformal coating on them and they are hard to contact.
You mentioned bypassing a bad one. Do you mean just shorting it out or replacing it with a diode?Leave a comment:
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Re: Sharp LC60LE810 with Lamp Error
OK, I will take it apart further and check the LEDs. Probably not till next week. I will report back when I have results. Thank you so much for all the help.Leave a comment:
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Re: Sharp LC60LE810 with Lamp Error
I've tried plugging in while holding VOL-, INPUT, POWER over a dozen times and it always starts with the flashing code. The only way I can get a solid "V" is by plugging in first, then pressing the 3 buttons.
When the "V" goes solid there is no voltage at all. I tried several meters and found one that is a little faster. It momentarily showed a reading, anywhere from 10-30 VDC. This short blip only occurs when the "V" goes from solid, back to flashing (at the end of the 10 seconds)
Do you...Leave a comment:
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Re: Sharp LC60LE810 with Lamp Error
I haven't been able to power up in error-ignore mode. What buttons are held down?Leave a comment:
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