Hello,
I managed to snag this TV for free but it has what appears to be a fixable issue. I apologize for the length of the post, but I think it will be helpful. I am still working on diagnosing the TV, and wouldn't mind some feedback. I'm trying to get the TV to predictably and reliably fail, so I can properly diagnose it. There are a number of boards available for it. The power board is BN44-00667a. I'll snag the main board model after I get home today.
The symptoms thus far:
Shuts down after some use, slow to start up, sometimes it doesn't start up, and HDMI port 1 doesn't work well or at all. HDMI port 2 works fine.
I have a DIRECTV box, and 2 Chromecast to test the inputs with. one of the Chromecasts is plugged into a wall plug, and the other was plugged into the USB port.
What I have done so far:
Initially it worked fine for a while, but after a few hours the problems began. This is why it was given to me.
I reset factory settings and updated to the latest firmware.
Watching DIRECTV for a few hours, TV started to stutter a small amount, after fast fwd or rewinding. Maybe it's the DIRECTV box. I switch inputs and the other one did not work at all. This behavior did not occur with the 32inch I had mounted prior. Continue watching, TV shuts down. attempt to restart it with power on remote. red light blinks with button pressing. after a minute or so, turns on. Shortly later it shuts down again. Red light is out completely.
Maybe it's a power board issue. Perhaps bad caps, that after getting hot from use were no longer delivering constant clean power? But then there is obvi an issue with the mainboard, (stuttering, HDMI switching). Maybe it isn't getting reliable power or maybe its broken somehow and going into a protect mode, thus shutting down.
I take a break as it won't turn on and clean up around the house. I come back 20-30 minutes later and the TV is on. hmm ok. time to focus on the mainboard.
When DIRECTV was plugged into HDMI 2, worked perfect, HDMI 1 reports no signal, or that it does not support HDCP. it'll occasionally display what's on DIRECTV but in 480 instead of 1080. Not long after the TV will shut down.
I attempt to rule out the HDMI cable by plugging in a Chromecast instead, which is supplied power from the USB port. (At this point, both HDMI ports have Chromecasts.) HDMI 1 reports no signal. unplug Chromecast power and plug back in. Chrome cast boot logo appears, then TV reports no signal. switch to HDMI 2 with other Chromecast, which works fine. Why will it display the boot screen from the Chromecast, but not accept a signal afterward??? Related to signal encryption, and thus a mainboard issue?
ok now it looks like a main board problem, specifically HDMI 1 related.
I remove the back panel and reinstall the mounting brackets so that I have quick access and can take it off the wall when it shuts down to further diagnose. I plan on unplugging the main board, and recording the result. I will try to test power outputs as well upon the next failure.
The TV shuts down; I unplug the inputs so that I can lay the TV on my bed which is just out of reach of the Chromecast (in HDMI 2) power cord. As it is laid down the bugger turns on again. I repeat this a few times. Might be something to do with main board and HDMI inputs or perhaps power drawn from USB port.
I take quick readings from the power out on the PSU to the mainboard while it is on, and it seems alright, but I only tested the easily assessable pins (I didn't have needle probes handy to get at all 14, just the top 7), as its getting late, and I need sleep. I didn't test the power while it has experienced a failure, as I couldn't get it to stay failed at this point.
I unplug the mainboard from the PSU while its lying flat but on. Everything kicks off for second and the backlight kicks back on. Not the most informative test as I would like to try this when its shut down from failure.
I observed 1 capacitor that could be ever so slightly bulged on the PSU. Hard to tell, and probably wouldn't hurt to swap it out, or the other electrolytic caps for that matter. I noticed the repair kits for the TV have non electrolytic caps in them however.
With the back off and the Chromecast plugged into the USB, I can hear the high pitch whine from the PSU, and I can see the Chromecast light turn off/on as it the TV attempts to kick on and power is drawn from its USB, which only supplies power, when it's on. Its cycles maybe 4-5 times, after that it is successful or it gave up.
I unplugged the TV for while at another juncture after it failed, and it seems to work for a few hours, like it did when I initially got it from someone. Perhaps this clears the protect mode, which means mainboard? But then again it could be a power board issue causing the mainboard to enter protect mode, and thus not that informative on its own….so onward to systematic testing. One last subjective observation, it appears switching HDMI inputs hastens failure, but I haven't objectively measured this yet.
My plan of attack:
Test power AC/DC outputs/inputs while on, and when it shuts down, if I am able to do so. I should not forget to test USB power either. Test the fuse, why not its easy.
Leave inputs plugged in and on, when failure occurs. (Move bed closer so I don't have to remove active inputs) This should hopefully narrow down if the HDMI or USB is causing the issue. I'll unplug the other boards systematically to rule out the offending board, and narrow down to component if I can.
If it's a main board failure, they cost 30 bucks and it's an easy swap. If it's a power board and it's just an electrolytic cap issue, then I don't mind swapping it out. If Its more complicated, then I'll just buy a refurb for 17.50 and swap it out, as the effort vs money is definitely not there for this. I feel like I'm missing something obvious for testing/diagnosing and I wouldn't mind some feedback.
Thank you for reading this far and for any help thrown my way.
I managed to snag this TV for free but it has what appears to be a fixable issue. I apologize for the length of the post, but I think it will be helpful. I am still working on diagnosing the TV, and wouldn't mind some feedback. I'm trying to get the TV to predictably and reliably fail, so I can properly diagnose it. There are a number of boards available for it. The power board is BN44-00667a. I'll snag the main board model after I get home today.
The symptoms thus far:
Shuts down after some use, slow to start up, sometimes it doesn't start up, and HDMI port 1 doesn't work well or at all. HDMI port 2 works fine.
I have a DIRECTV box, and 2 Chromecast to test the inputs with. one of the Chromecasts is plugged into a wall plug, and the other was plugged into the USB port.
What I have done so far:
Initially it worked fine for a while, but after a few hours the problems began. This is why it was given to me.
I reset factory settings and updated to the latest firmware.
Watching DIRECTV for a few hours, TV started to stutter a small amount, after fast fwd or rewinding. Maybe it's the DIRECTV box. I switch inputs and the other one did not work at all. This behavior did not occur with the 32inch I had mounted prior. Continue watching, TV shuts down. attempt to restart it with power on remote. red light blinks with button pressing. after a minute or so, turns on. Shortly later it shuts down again. Red light is out completely.
Maybe it's a power board issue. Perhaps bad caps, that after getting hot from use were no longer delivering constant clean power? But then there is obvi an issue with the mainboard, (stuttering, HDMI switching). Maybe it isn't getting reliable power or maybe its broken somehow and going into a protect mode, thus shutting down.
I take a break as it won't turn on and clean up around the house. I come back 20-30 minutes later and the TV is on. hmm ok. time to focus on the mainboard.
When DIRECTV was plugged into HDMI 2, worked perfect, HDMI 1 reports no signal, or that it does not support HDCP. it'll occasionally display what's on DIRECTV but in 480 instead of 1080. Not long after the TV will shut down.
I attempt to rule out the HDMI cable by plugging in a Chromecast instead, which is supplied power from the USB port. (At this point, both HDMI ports have Chromecasts.) HDMI 1 reports no signal. unplug Chromecast power and plug back in. Chrome cast boot logo appears, then TV reports no signal. switch to HDMI 2 with other Chromecast, which works fine. Why will it display the boot screen from the Chromecast, but not accept a signal afterward??? Related to signal encryption, and thus a mainboard issue?
ok now it looks like a main board problem, specifically HDMI 1 related.
I remove the back panel and reinstall the mounting brackets so that I have quick access and can take it off the wall when it shuts down to further diagnose. I plan on unplugging the main board, and recording the result. I will try to test power outputs as well upon the next failure.
The TV shuts down; I unplug the inputs so that I can lay the TV on my bed which is just out of reach of the Chromecast (in HDMI 2) power cord. As it is laid down the bugger turns on again. I repeat this a few times. Might be something to do with main board and HDMI inputs or perhaps power drawn from USB port.
I take quick readings from the power out on the PSU to the mainboard while it is on, and it seems alright, but I only tested the easily assessable pins (I didn't have needle probes handy to get at all 14, just the top 7), as its getting late, and I need sleep. I didn't test the power while it has experienced a failure, as I couldn't get it to stay failed at this point.
I unplug the mainboard from the PSU while its lying flat but on. Everything kicks off for second and the backlight kicks back on. Not the most informative test as I would like to try this when its shut down from failure.
I observed 1 capacitor that could be ever so slightly bulged on the PSU. Hard to tell, and probably wouldn't hurt to swap it out, or the other electrolytic caps for that matter. I noticed the repair kits for the TV have non electrolytic caps in them however.
With the back off and the Chromecast plugged into the USB, I can hear the high pitch whine from the PSU, and I can see the Chromecast light turn off/on as it the TV attempts to kick on and power is drawn from its USB, which only supplies power, when it's on. Its cycles maybe 4-5 times, after that it is successful or it gave up.
I unplugged the TV for while at another juncture after it failed, and it seems to work for a few hours, like it did when I initially got it from someone. Perhaps this clears the protect mode, which means mainboard? But then again it could be a power board issue causing the mainboard to enter protect mode, and thus not that informative on its own….so onward to systematic testing. One last subjective observation, it appears switching HDMI inputs hastens failure, but I haven't objectively measured this yet.
My plan of attack:
Test power AC/DC outputs/inputs while on, and when it shuts down, if I am able to do so. I should not forget to test USB power either. Test the fuse, why not its easy.
Leave inputs plugged in and on, when failure occurs. (Move bed closer so I don't have to remove active inputs) This should hopefully narrow down if the HDMI or USB is causing the issue. I'll unplug the other boards systematically to rule out the offending board, and narrow down to component if I can.
If it's a main board failure, they cost 30 bucks and it's an easy swap. If it's a power board and it's just an electrolytic cap issue, then I don't mind swapping it out. If Its more complicated, then I'll just buy a refurb for 17.50 and swap it out, as the effort vs money is definitely not there for this. I feel like I'm missing something obvious for testing/diagnosing and I wouldn't mind some feedback.
Thank you for reading this far and for any help thrown my way.