Model: PN50C450B1DXZA
Symptoms: Colored thin vertical lines in two places on the right side of screen. One approx. 2 inches wide and the other maybe 1/2" wide. Developed a different issue upon reinserting the cards. Upon power on, screen flashes brightly, then solid black. Red standby LED light flashes red 5 times and stops. Logic board light flashes about 5 seconds on, and two seconds off.
So, I was messing with an old TV that got lines in it a few months back since I have some extra time on my hands. I have read just about every justanswer reply, badcaps article, and off the wall google result page imaginable on this model and its original issue. I've taken all of my voltages and most were within a few volts of spec, and were adjusted to be precise.
Voltages Spec/Actual:
VS: 209/209.6
VA: 55/55
VSC: -178/-178 ****drops to -175 following the flash***
VE: 86/86
2VE: 74/ unable to find test point.
Initially, my only problem was that it had vertical colored lines, so I figured it was the Y buffer board. I was going to replace the Y buffer and Y main at the same time as I read that sometimes the Y main can fault out the Y buffer, generally ruining the replacement.
Physical tests:
Disconnect Y main power supply = Cannot remember... can't reattempt in current state.
Disconnect Y buffer ribbon cable = Left one black horizontal line across screen. Black through sections which colored lines appeared.
Disconnect X main power supply cable = Cannot remember... can't reattempt in current state.
Swap ribbon cables coming from logic board to E and F buffer boards in hope to get the video to swap sides, putting the colored bars on opposite side to test if logic output was bad = No Video
I removed the Y main, Y buffer and Logic Control boards to do some short testing as described in the video by Tom66 on Youtube. I found some shorts to ground in the Y buffer. At this point I came across another good justanswer article and the little box popped up to prompt me to ask my own question. I wanted a photo of my issue to accompany, so I reinstalled the boards. I was careful to seat each ribbon cable and clamp fully, and all connectors. I DID only place a few mounting screws to hold the boards in place... not sure if that could have caused some arcing, ruining some more stuff.
Upon power up, I saw a bright flash, the screen went dark, and the standby LED was flashing red 5 times. I looked at the logic board and instead of the "heartbeat," it had an on/off of 5 sec/2 sec.
This morning, I did some more power tests at each connector and came up with the following short to ground/continuity results:
Y Main
CN5801
Pin 3 - OC1
Pin 9 - YSC
X Main
CN7401
Pin 13 - VDD
CN4001
Pin 14 & 15 - VDD
Main
C123D
Pin 7 - B5V
Pin 8 - B5V
Pin 12 - B5V
CN710
Pin 9 - A3.3V
Pin 10 - GND (Has no Ground)
I was only able to find one fuse on the SMPS/PSU board, and it tests good.
I'm at a complete stop, and have no idea what this could be, or how to fix it. I've followed the Fast Track Troubleshooting manual and tried to jumper the logic board and main>SMPS cable to display the test patterns, but I got nothing.
I'm still new to troubleshooting these, so work with me, please! Thank you in advance!
Symptoms: Colored thin vertical lines in two places on the right side of screen. One approx. 2 inches wide and the other maybe 1/2" wide. Developed a different issue upon reinserting the cards. Upon power on, screen flashes brightly, then solid black. Red standby LED light flashes red 5 times and stops. Logic board light flashes about 5 seconds on, and two seconds off.
So, I was messing with an old TV that got lines in it a few months back since I have some extra time on my hands. I have read just about every justanswer reply, badcaps article, and off the wall google result page imaginable on this model and its original issue. I've taken all of my voltages and most were within a few volts of spec, and were adjusted to be precise.
Voltages Spec/Actual:
VS: 209/209.6
VA: 55/55
VSC: -178/-178 ****drops to -175 following the flash***
VE: 86/86
2VE: 74/ unable to find test point.
Initially, my only problem was that it had vertical colored lines, so I figured it was the Y buffer board. I was going to replace the Y buffer and Y main at the same time as I read that sometimes the Y main can fault out the Y buffer, generally ruining the replacement.
Physical tests:
Disconnect Y main power supply = Cannot remember... can't reattempt in current state.
Disconnect Y buffer ribbon cable = Left one black horizontal line across screen. Black through sections which colored lines appeared.
Disconnect X main power supply cable = Cannot remember... can't reattempt in current state.
Swap ribbon cables coming from logic board to E and F buffer boards in hope to get the video to swap sides, putting the colored bars on opposite side to test if logic output was bad = No Video
I removed the Y main, Y buffer and Logic Control boards to do some short testing as described in the video by Tom66 on Youtube. I found some shorts to ground in the Y buffer. At this point I came across another good justanswer article and the little box popped up to prompt me to ask my own question. I wanted a photo of my issue to accompany, so I reinstalled the boards. I was careful to seat each ribbon cable and clamp fully, and all connectors. I DID only place a few mounting screws to hold the boards in place... not sure if that could have caused some arcing, ruining some more stuff.
Upon power up, I saw a bright flash, the screen went dark, and the standby LED was flashing red 5 times. I looked at the logic board and instead of the "heartbeat," it had an on/off of 5 sec/2 sec.
This morning, I did some more power tests at each connector and came up with the following short to ground/continuity results:
Y Main
CN5801
Pin 3 - OC1
Pin 9 - YSC
X Main
CN7401
Pin 13 - VDD
CN4001
Pin 14 & 15 - VDD
Main
C123D
Pin 7 - B5V
Pin 8 - B5V
Pin 12 - B5V
CN710
Pin 9 - A3.3V
Pin 10 - GND (Has no Ground)
I was only able to find one fuse on the SMPS/PSU board, and it tests good.
I'm at a complete stop, and have no idea what this could be, or how to fix it. I've followed the Fast Track Troubleshooting manual and tried to jumper the logic board and main>SMPS cable to display the test patterns, but I got nothing.
I'm still new to troubleshooting these, so work with me, please! Thank you in advance!
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