Cheers dude glad i found your video, Was trying to work out my issue with an identical TV and now thanks to you and your video i worked out it's my top YDRVTP board! Thank you!
i had the same tv last week with the same issue,stuggled finding a replament board,found 1 on the inernet,just a warning to others,be carefull the replacment board did the same,gave in and orderd new ic's and sent the replacment back.new ic chips turned up and changed them under the reflow heater.tv worked a treat so as an after thought i installed fans to keep the buffer boards cool in the future :o)ps it makes a change for me to be ahead of you on a repair lol,keep up the good work,your vids inspire me and others :o)
great video! I had same thing and same bad top chip on upper y buffer board but on samsung hpt5054 plasma tv. I replaced y buffer but y sustain board was bad too. crap load of parts went bad transistors on heatsink and more, there's repair kits available but none worked for me. is it possible if plasma display panel is bad no matter what board is repaired it will destroy any board in circuit, how test for bad panel besides physical damage? I have working on TVs since 1999 so I know the basics.
Greta video....I have the same TV with the same similar problem (no picture sound only) and when removing the upper buffer board it did the same thing, the bottom half gave me a similar picture like in your video. Is it safe to say the upper buffer board needs replacing. Now I did try removing the lower buffer board only and go nothing.
Hi norcal715, I have the exact same LG Plasma TV (50PG20). What would you recommend to starting troubleshooting if there's no sound, picture or light at the power switch? thanks in advance for any feedback that can get me started with attempting to diagnosing these problems.
+norcal715 I have a question for the same exact problem with a slightly different LG set. Power supply clicks, VA and VS voltages are good at power supply and the test points on the Y-Main board. I have replaced the mainboard and issue remains. After watching your video I tried power tv on with just 1 y-buffer board connected - tested with both buffers, but I did not get anything on the screen like you did. My t-con/control board in the center of the tv has a solid green light on it so seems like it is good up until there. Before I go dumping lots of money into, does it sound like the Y-Main board is bad? I don't see any bad caps anywhere.
Where to look if in my case when all connected Va and Vs voltages getting down till 0, but no shorter looping. If disconnect y buffer, then voltages are ok.
this discontinued set has been impossible to find fresh boards for. The lower buffer board had ic 204 fried. Power surge is suspected, because our small city has outages during high winds or ice storms, and it was part of a bank of tvs in a bar, where I'm not sure if they surge protected the 120vac circuits. My board is a Rev H, which has no heatsinks. repair is only option, as LG and others will not produce a substitute product.
can you help me with my old lg? it is turning on but has bad picture, even the "no signal" text has horizontally shifted ghosting pixels, any input has multiple shifted ghost columns... it is like when on an lcd the ribbon cable has a break or freqvency shift but I don't know how plasma works. no visual issue inside, no puffed capacitors etc...
I have the same model, It has the standby light but when I press the power button nothing happens. could you point me in the right direction of what could be wrong. Thanks in advance
One of the best. I have a free tv sitting for a long time, bad zsus as no picture, then a picture with a few pink lines after swapped zsus and power supply (when plugged tv in, would turn on itself so swapped power supply also, stopped this issue) and it was working but in my quest to "tune" the pink vertical lines that would change to black and be less noticeable when changing the VS and VA blindly like a fool as well as the setup and setDN? Also whatever the daughterboard on the Ysus does or is called as well as in the othe grey plastic voltage knobs? Three on my Ysus? Anyway, any reason why I would of had it working minus three pink vertical lines always in same spot (buffer board? I don't see a buffer in the bottom on my PL4260N by HP but I will look down deeper. I had sparking, not once, twice, three times but turned it off, re seated all the working Y buffer boards ribbons and it started arcing on me in various spots and looks to have blown at least two IC's. I think my issue is the logic for the pink lines which isn't so bad and to get a new buffer now (Ysus's fuses did not blow, finger crossed!) and learning how to truly set the voltages up. Did I probably do this by messing with the knobs on Ysus or are they okay once VS and VA from the power supply is set and okay as in can't blow the buffer and this was going to happy anyway most Likely and I just happened to see the grand finale? I'm so frustrated as had it and wish I never touched the voltage knobs (what are they really called, setup, setDN?, etc) but to late. What would you suggest I do first and why do you think it blew if had to guess? Over voltage by my dumb ass or just age? Again, I think if I'm lucky Now a Ybuffer and logic should do the trick as in fix the blown buffer chips that were blowing and arcing in my face and the logic may clear up the pink lines? I need to learn in depth how to set the knobs though on all boards and do the VS and VA first. Can one do the VS and VA without some boards in as in whilst awaiting replacement if use the factory numbers printed on mine? Thanks in advance.. it had a beautiful picture and second to none Sound while it lasted for three or four hours! Hah, yes I am an idiot for adjusting anything without a volt meter. Where to go now? I hope it didn't burn my ribbons? Chances of that? Why would of arc and keep arcing if one or two went bad in a row, normal or a symptoms of something I seem to have done? Suggestions, laughs, comments, anything at all is appreciated greatly! Thanks, Stephen
My real goal was to get this up and going then mod a fan to zsus and Ysus over the ic chips if I could find a 12v rail. Back to getting a picture. I really need a superb tutorial on how to set all knobs and voltages. Especially since ordering parts on ebay how can one know if knobs were turned and people only ever comment on VS and VA.
BTW: Y buffer can blow Ysus but Ysus not usually ybuffer? Sorry for so many questions but I want to get it right this time, if it's still possible by ordering buffer and a.....logic or x?.. praying Ysus didn't go and hoping I learn how all knobs work and which ones blow stuff out and how to set, etc..
What was the procedure for removing the heat sink from the PDP chips? It looked as if it was epoxied on. Also, if you have a Panasonic plasma set with an undamaged screen, is there a straightforward check you can make to see if the panel is good? I have a set where the protect circuit keeps tripping, but the sustain and buffers appear to be good.
norcal715 It's a TH-50PZ77U with 7 blinks. I've gone through the flowcharts. Flowchart says bad lower buffer (SD). I've swapped in a couple of new lower buffers and also tried a new Y sustain (SC) with no improvement. I don't measure any shorts on the lower buffers. In the past, the set would run for week and then fail back to protected mode. I can see the lower half of the picture start to degrade just be it goes into protected mode. Set runs fine if I pull the lower buffer although I obviously have only half the picture.
i have the same tv.. i unplugged the top buffer board and i get a picture but its very pixelated and gets a box that pops up... is there more wrong with this unit before i spend 100 on a new buffer board?
I have a LG 60PN5700 UA. It is stuck on logo screen. This started about 2 yrs ago. I put the tv up and pulled it out this week. To my surprise the tv started up properly and had a perfect pic for a few hours. I turned it off and when I turned it back on it would not go past logo screen.
I have a Sony SA-W2500 powered sub woofer that cuts out after 3 seconds when volume is applied. I have been all over the internet and there is nothing about this model on repairing the amp. Please msg me if you can, I'm out of options --__--
