About a week and a half ago this TV was traded in to me with the complaint: upon turning it on one morning a white blob slowly spread across the screen. Before I got it the TV had been sitting about 3 weeks. I also found the RF IN connector was missing. I turned it on for evaluation and got the splash screen/menus.
I installed a 75ohm RF connector, repaired several bad grounds on the power board and chassis, checked all boards for loose screws and cleaned the entire inside of the TV. After all appeared well, the TV was tested for 40 hours and was subsequently put up for sale.
Fast forward to noon today, and with a seriously interested party I pulled it out of storage and set it up in the house. All was well, the TV turned on just fine and appeared to have no problems. I prefer to run them while awaiting an appointment setting to make sure all was OK, and everything appeared good. I even tested all the HDMI's with my video camera to make sure they were working.
About 3 hours later and a buyer on the way I carried it out to my shop to set it up for viewing. I plugged it in, installed a VHF antenna via 75ohm jack and turned it on to re-scan channels since I only use a bread tie as an antenna in the house, inserted in to the RF jack. It's length isn't sufficient to receive RF channel 10 which has the best 1080p set-up locally, hence the reason to re-scan.
As I was scanning the picture went out, then the screen turned totally white and then the picture went back to black and came back. This repeated twice during the channel scan. Once it was completed the sound came up, but the picture was delayed by almost a second and a half. When changing channels the sound is near immediate but the picture takes one to 1 1/2 seconds to show.
A factory reset made no difference and the problem continued.
I knew this wasn't right, and I won't sell a TV that way. I called the buyer and told her to turn around. This is the SECOND slap in the face this week and in a damn row too. I had a buyer coming for that Toshiba 50L1350U you all helped me with some time ago. Took it out to the shop, plugged it in, turned it on and the backlights went out. FML!
My first impression was a main board issue, but in an attempt to be thorough here's what I did:
1) Check connections/remove and inspect LVDS cable. The terminals at the main board were distorted and dirty. Replace LVDS (had it here), cleaned connections at main board and t-con and re-test. The white flash did not come back after this point or in any subsequent tests but the flashing picture and delayed picture were still there
2) Check to see if backlight flash is responsible: Active LED zone behind the menu did go out and come back on. Performed flashlight test when picture/active LED zone loss occurred and there was no image on the screen.
3) The active LED zone feature was disabled and the above tests re-run. Backlights remained on across the entire display and the picture itself is confirmed to be flashing.
4) I then checked t-con supply voltage from the main board as the picture flashed. 11.8v is present all the time at capacitor CP6 which is off the output side of the t-con fuse.
5) I removed the t-con and both FFC's from the TV. The FFC contacts were very tarnished looking but otherwise OK so they were all cleaned. I had a confirmed good t-con so I installed it, never believing it was the problem.....but I had one so what the hell right? As I suspected the problem is still present.
During regular operation on a channel or app the picture does not flash. There is a noticeable improvement in picture quality after cleaning all the signal cables.
From this point I think I'm going to need some direction on troubleshooting. I've gone as far as I can go since I do not have a good main board. If I did I'd probably toss it in there and it would likely solve the problem. Can anyone help me with this one?
Thanks
I installed a 75ohm RF connector, repaired several bad grounds on the power board and chassis, checked all boards for loose screws and cleaned the entire inside of the TV. After all appeared well, the TV was tested for 40 hours and was subsequently put up for sale.
Fast forward to noon today, and with a seriously interested party I pulled it out of storage and set it up in the house. All was well, the TV turned on just fine and appeared to have no problems. I prefer to run them while awaiting an appointment setting to make sure all was OK, and everything appeared good. I even tested all the HDMI's with my video camera to make sure they were working.
About 3 hours later and a buyer on the way I carried it out to my shop to set it up for viewing. I plugged it in, installed a VHF antenna via 75ohm jack and turned it on to re-scan channels since I only use a bread tie as an antenna in the house, inserted in to the RF jack. It's length isn't sufficient to receive RF channel 10 which has the best 1080p set-up locally, hence the reason to re-scan.
As I was scanning the picture went out, then the screen turned totally white and then the picture went back to black and came back. This repeated twice during the channel scan. Once it was completed the sound came up, but the picture was delayed by almost a second and a half. When changing channels the sound is near immediate but the picture takes one to 1 1/2 seconds to show.
A factory reset made no difference and the problem continued.
I knew this wasn't right, and I won't sell a TV that way. I called the buyer and told her to turn around. This is the SECOND slap in the face this week and in a damn row too. I had a buyer coming for that Toshiba 50L1350U you all helped me with some time ago. Took it out to the shop, plugged it in, turned it on and the backlights went out. FML!
My first impression was a main board issue, but in an attempt to be thorough here's what I did:
1) Check connections/remove and inspect LVDS cable. The terminals at the main board were distorted and dirty. Replace LVDS (had it here), cleaned connections at main board and t-con and re-test. The white flash did not come back after this point or in any subsequent tests but the flashing picture and delayed picture were still there
2) Check to see if backlight flash is responsible: Active LED zone behind the menu did go out and come back on. Performed flashlight test when picture/active LED zone loss occurred and there was no image on the screen.
3) The active LED zone feature was disabled and the above tests re-run. Backlights remained on across the entire display and the picture itself is confirmed to be flashing.
4) I then checked t-con supply voltage from the main board as the picture flashed. 11.8v is present all the time at capacitor CP6 which is off the output side of the t-con fuse.
5) I removed the t-con and both FFC's from the TV. The FFC contacts were very tarnished looking but otherwise OK so they were all cleaned. I had a confirmed good t-con so I installed it, never believing it was the problem.....but I had one so what the hell right? As I suspected the problem is still present.
During regular operation on a channel or app the picture does not flash. There is a noticeable improvement in picture quality after cleaning all the signal cables.
From this point I think I'm going to need some direction on troubleshooting. I've gone as far as I can go since I do not have a good main board. If I did I'd probably toss it in there and it would likely solve the problem. Can anyone help me with this one?
Thanks
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