A friend called, a panel I helped install, had just made a pop and lost the picture, still had sound. No previous issues.
Apparently, upon their further toggling there was another smaller pop. When I got there a few days later, No Sound, No glow, the front standby LED counting out a sequence. I pulled the back and the main/control board LED was in the 5 sec fault mode.
I followed a diagnostic that Tom669 had helped a similar set owner with, at AVS:
https://www.avsforum.com/forum/167-p...s-look-ok.html
I disconnected the X Main/buffer two piece from the PS and it's daisy chain to the Y Main, but left the Ribbon from Ymain to control/main in place. Vs powered to the panel number of 208 and dropped as expected.
Tom's recommend in that thread, was to replace both X main and Y main.
A TV shop friend offered to look at Y main and X main. He looked for continuity on the IC's on the backside of the boards. I saw a couple of shorts on the Y, and the way those chips were soldered, I figured another board was probably my best bet.
My mentor's thought was, only one board was needed.
____
I installed a new to us, Y main and the old X main.
I'm not positive but I think I now had the one second LED blink, definately had standby acting right and a glow on start attempt, but no picture yet.
Took a moment and saw that I missed a small connector from the lower buffer area to the X buffer.
Now, all is well. Set starts and runs fine. Restarts fine when the back is in place, and runs all afternoon.
Then won't restart after an hour break. The set is left off 2 days and then starts fine. A day or two later starts fine and runs for 4 hours. When I'm on way back to that side of town, she won't restart.
I'm armed with freeze spray and a heat gun JIC. Along with more posted information and YouTube vids.
(We're not doing multiple button pushes to see if it'll start. I know something's wrong.)
So, at this point, the green LED is flashing the fault sequence of once every 5 seconds. I again disconnected the X main section from the PS and the connection between the Y main and X main, to establish the PS was ramping up to 208 before falling back as it should.
On a Coppell U-Tube, They were working on a 64” version of this model number, and he left the boards connect from the PS but disconnected the ribbon between Ymain and control/main, to confirm fault on Y main. (My guess is those models didn't have Y main and X main daisy chained, so maybe it isolated Y main?)
https://www.youtube.com/watch?v=NT4F3sU-qfY
I probably should have checked Vscan and Ve, but failed to. I'm wanting to assume Y main is still mostly intact.
I proceeded with a cable connector/ribbon cable dance to try and isolate Ymain from Xmain. All the while, I have the once per 5 second fault light.
I'm starting to wonder if the control/main is a problem as well. (The scenario has been, when she comes up, it's fine, and stays on until put in standby.)
I see a small connector between X main and control/main. When I disconnect that as well, I should just have control/main and PS (and links to lower buffers).
I now have the once per second green LED, and PS is happily holding Vs at 208. So, I guess I have confidence that at least half of the control/main is OK?
The Xmain is econmically priced. I now want to pull the Ymain and Xmain again, and learn how to do as good a job as I can with the DMM to check components. (I realize the cap issues will have to be figured a different way.)
My two questions: Is there a way to test the Xmain , really?
As another has asked: There are stories about one board death leading to another. In Tom66 remarks in the AVS thread, it looks like this set is a candidate,
Can a prevoiusly hurt Xmain now ruin a new to us, functioning Ymain ?
IOW's can you put yourself in a destrucive do loop?
So, what is one looking for when checking boards, before install, to mitigate board on board violence?
Thanks for looking and helping.
PS: Yes I did cold spray some of the little blue caps on the Y main, to no avail.
Apparently, upon their further toggling there was another smaller pop. When I got there a few days later, No Sound, No glow, the front standby LED counting out a sequence. I pulled the back and the main/control board LED was in the 5 sec fault mode.
I followed a diagnostic that Tom669 had helped a similar set owner with, at AVS:
https://www.avsforum.com/forum/167-p...s-look-ok.html
I disconnected the X Main/buffer two piece from the PS and it's daisy chain to the Y Main, but left the Ribbon from Ymain to control/main in place. Vs powered to the panel number of 208 and dropped as expected.
Tom's recommend in that thread, was to replace both X main and Y main.
A TV shop friend offered to look at Y main and X main. He looked for continuity on the IC's on the backside of the boards. I saw a couple of shorts on the Y, and the way those chips were soldered, I figured another board was probably my best bet.
My mentor's thought was, only one board was needed.
____
I installed a new to us, Y main and the old X main.
I'm not positive but I think I now had the one second LED blink, definately had standby acting right and a glow on start attempt, but no picture yet.
Took a moment and saw that I missed a small connector from the lower buffer area to the X buffer.
Now, all is well. Set starts and runs fine. Restarts fine when the back is in place, and runs all afternoon.
Then won't restart after an hour break. The set is left off 2 days and then starts fine. A day or two later starts fine and runs for 4 hours. When I'm on way back to that side of town, she won't restart.
I'm armed with freeze spray and a heat gun JIC. Along with more posted information and YouTube vids.
(We're not doing multiple button pushes to see if it'll start. I know something's wrong.)
So, at this point, the green LED is flashing the fault sequence of once every 5 seconds. I again disconnected the X main section from the PS and the connection between the Y main and X main, to establish the PS was ramping up to 208 before falling back as it should.
On a Coppell U-Tube, They were working on a 64” version of this model number, and he left the boards connect from the PS but disconnected the ribbon between Ymain and control/main, to confirm fault on Y main. (My guess is those models didn't have Y main and X main daisy chained, so maybe it isolated Y main?)
https://www.youtube.com/watch?v=NT4F3sU-qfY
I probably should have checked Vscan and Ve, but failed to. I'm wanting to assume Y main is still mostly intact.
I proceeded with a cable connector/ribbon cable dance to try and isolate Ymain from Xmain. All the while, I have the once per 5 second fault light.
I'm starting to wonder if the control/main is a problem as well. (The scenario has been, when she comes up, it's fine, and stays on until put in standby.)
I see a small connector between X main and control/main. When I disconnect that as well, I should just have control/main and PS (and links to lower buffers).
I now have the once per second green LED, and PS is happily holding Vs at 208. So, I guess I have confidence that at least half of the control/main is OK?
The Xmain is econmically priced. I now want to pull the Ymain and Xmain again, and learn how to do as good a job as I can with the DMM to check components. (I realize the cap issues will have to be figured a different way.)
My two questions: Is there a way to test the Xmain , really?
As another has asked: There are stories about one board death leading to another. In Tom66 remarks in the AVS thread, it looks like this set is a candidate,
Can a prevoiusly hurt Xmain now ruin a new to us, functioning Ymain ?
IOW's can you put yourself in a destrucive do loop?
So, what is one looking for when checking boards, before install, to mitigate board on board violence?
Thanks for looking and helping.
PS: Yes I did cold spray some of the little blue caps on the Y main, to no avail.
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