Re: LG 50PS60 Half Screen
-Vy stable at 180V; VSCAN unstable. I will look for an upper buffer board.
Thanks!
jfcurran
New Member
Last Activity: 04-22-2021, 05:39 PM
Joined: 09-06-2018
Location: Alexandria, Ohio
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Re: LG 50PS60 Half Screen
So, to summarize the current behavior.
On a cold start (TV off for several hours, below-average room temperature), the TV shows the bottom half of the image as depicted in the photo.
After a few off/on cycles, the screen just flashes and stays blank.
While the bottom half is working, the waveform at the buffer boards even/odd test points is about 400V peak-to-peak.
While the set is blank, the waveform is about 40V peak-to-peak and it looks more like logic signals than analog. Again, this is for both the...Leave a comment:
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Re: LG 50PS60 Half Screen
Hi,
No the resistor was cool while running the upper only.
I tested across the obvious capacitors on the buffer boards - all the same resistance. I also checked voltages on the power connectors - these checked out as well on both boards. During these tests, the set was in its original failure mode (lower display working, upper dark, streaky, speckled)
Also took the YSus board out and looked very carefully for bad solder joints (this time I removed the insulating strips). Nothing wrong that I could see.
Am wondering...Leave a comment:
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Re: LG 50PS60 Half Screen
OK - upper buffer board removed; all screws in tight.
Here's a photo of the Y-Sus board driving only the lower buffer board (upper board removed).
I still need to test the capacitors on the upper buffer board. Will get back with that.
BTW - while this image was displaying, the wirewound resistor on the Y-Sus board got *really* hot. The odor is what got my attention. I have not smelled that since I have been working with this TV.
Once the set went back to flickering to black on power-up, the resistor...Leave a comment:
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Re: LG 50PS60 Half Screen
OK I will try that. But it looks like signals travel through the upper to the lower? See ribbon cables in the photo.
Thanks,
Jim...Leave a comment:
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Re: LG 50PS60 Half Screen
Removed the upper buffer. Could not find any shorts (watched several Youtube videos on the topic).
Inspected Y-Sustain board for heat issues, bad solder joints - found none but did not look under the wide rubber strips. Any advice on removing them?
After replacing all boards I powered it up and the bottom half showed the Chromecast bootup and the upper half showed random lines and specks. But eventually the set would go black. Subsequent toggling on and off just yielded a bit of a flash and then darkness.
The Y-Sus...Leave a comment:
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Re: LG 50PS60 Half Screen
Thanks folks - I will check those connections.Leave a comment:
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LG 50PS60 Half Screen
Hi,
I came into a discarded LG 50PS60. This morning, when cold, the TV put out a good HD picture from a Chromecast attached to HDMI 4.
But about 30 minutes later the upper half of the display went dark except for the odd multi-color sparkle or single horizontal line. Eventually, the entire screen goes dark. But audio continues throughout. After a little while, the TV does seem to lock up.
Does this point to any specific failure?
Thanks for any advice!
Jim... -
Re: TV Sony NSX-40GT1 (Power Supply)
Thank you! I had the same blink pattern and this worked great for me. I ended up using TK5A50D MOSFETs as they were the recommended replacement for 2SK3563. I could not source the Panasonic part and used a 1/2 watt fusible resistor (Vishay NFR25H0004707JA500)
Thanks again!Leave a comment:
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