>> >>
>> >On Saturday, October 9, 2021 at 12:17:58 PM UTC-4, legg wrote: >> >
>> >> >> . . . so its not just a defective RCD snubber.
>> >> >>
>> >> >> RL
>> >> >
>> >> >Get a bright light and go over the entire display slowly looking for a single burned pixel. If you find one, the display is junk. Not common on LG but not unheard of either.
>> >> That would do it? - cause this repeated component failure? >> >>
>> >> Couldn't the connections to that single pixel be disconnected,
>> >> producing a black t on the screen, and non-popping parts?
>> >>
>> >> RL
>> >
>> >Yes. Learned from experience. I never touched a plasma until I carefully went over the entire display, including right to the edges. A single burned pixel meant the end of the road.
>> >
>> >I repaired at least a hundred of those series when I was an LG ASC. The vast majority were bad IPMs on one sustain or the other, and once in a while a bad buffer board. I don't recall ever seeing a bad control, main, or power supply.
>> >
>> I came across a service advisory for this model that
>> gave me a chuckle:
>>
>> "2006 LCD, PDP, & MDPs that use the ARM CPU & Micronix Flash Memory. >>
>> Symptom:
>>
>> During a specific date range the customer may turn on the TV and there
>> will be no video
>>
>> or audio. The problem will first occur: Jun 20th, 2006, 14:03 ~ Jun
>> 21st, 08:14. Then
>>
>> it repeats every 194 days.
>>
>> Solution:
>>
>> Temporary fix is a hard reset (unplug for a few seconds). New firmware
>> is available as
>>
>> a permanent fix. The update needs to be done by a service center. >>
>> Models:
>>
>> 32LC2D, 37LC2D, 42LC2D, 42PC3DV, 42PC3DVA, 42PC3D, 50PC3D, 50PX2D, >> 50PX2DC.
>>
>> Tools Required:
>>
>> Computer
>>
>> Null Modem Serial Cable
>>
>> Tools Supplied:
>>
>> Instructions
>>
>> Firmware Files
>>
>> DTVLab Update Software
>>
>> Versions:
>>
>> 32LC2D-UD : Ver3.06.1
>>
>> 37LC2D-UD : Ver3.06.1
>>
>> 42LC2D-UD : Ver3.05.1
>>
>> 42PC3DV-UD(42PC3DVA-UD) : Ver3.06.1
>>
>> 42PC3D-UD : Ver3.07.1
>>
>> 50PC3D-UD : Ver3.07.1
>>
>> 50PX2D-UD(50PX2DC-UD) : Ver3.10.1
>>
>> 42PC3DV-UD,42PC3DVA-UD : the same as S/W
>>
>> 50PX2D-UD,50PX2DC-UD : the same as S/W "
>>
>> Would have thought that such an advisory would have
>> generated a surplus of support tools that would
>> remain for later employment . . . but nada.
>>
>> RL
>
>Honestly, I don't remember that at all. If I read that bulletin, then I forgot about it. I also don't recall ever getting complaints about that problem.
After replacing the 74AC540s on the YSUS board, a 2nd buffer board replacement didn't pop it's top 47R resistor - although I'm only running the device long enough to scope a few waveforms and take a few screen shots - so I don't know for sure whether the resisisor or a similar part will fail again, given the opportunity.
The buffer output voltage still does not follow the YSUS output below about -50V.
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I now get a lit panel with greenish horizontal streaks and a red-yellowish vertical section that hops back and forth across the display. This was what I was looking at for very short time periods, previously, before the buffer board resistor failure blanked out the bottom sections.
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Do I need a white screen (or any) input signal to go further? Most TV's have a built-in "no signal source detected' display pattern . . .RL