New 55" LG SM8600 keeps rebooting unless I give it the finger

BigH29

Member
Bought a 55" inch nanocell, model 55SM8600PUA, that was a display model at a local display store. They put it back in the original box and loaded it into my truck. I treated it like a baby at home and got it mounted tonight. It booted up as soon as I plugged it in, displayed a TV program for a couple seconds, and then rebooted again. It repeats this cycle forever. The reboot consistently happens 2-5 seconds after it comes on.

After some troubleshooting, I discovered that I can keep it from rebooting if I lightly hold my finger on the manual power button. I don't press it, just hold it there without any real pressure. If I do that, I can watch TV, change channels with the remote with my other hand, setup wifi. Hell, I even updated the software hoping that might fix it (yes, I stood there like a dope with my finger on the button while the update progress painfully ramped up to 100%).

Anyone ever seen something like this? This feels like a software issue or an interfering device to me, but who knows.

Here is what I know:
  • The TV did not act like this at the store. It stayed on just fine
  • The store seemed to have the TV connected to a different remote on the floor. They left the original in the box
  • We had problems getting the floor remote to work, but this was true of a several TVs.
  • The store had a soundbar plugged in
  • They left the power cord plugged in when they boxed it up. Not a fan of that, but it doesn't seem to be the problem

Here is what I have done
  • Checked the power cable for continuity. Seems to be fine
  • Jostled and re-connected the power cable. Doesn't seem to be an input power problem
  • Once I learned the finger trick, I did a factory reset
  • Setup WIFI and sat through 2 software updates until I was on the latest
  • Disabled and cleared all timers
  • Disabled settings involved with going to sleep, screensavers, etc. Think I got them all, but hard to say
  • Made sure the system time was correct
  • Removed batteries from the remote hoping maybe it was telling the TV to turn off. Didn't work
  • Turned off nearby Alexa's, lights, Sonos, and bluetooth devices
I feel like the device is shutting itself off, or allowing something to turn it off. After playing with it, I learned that if I stay busy on the remote (iow, keep cycling through menus), I can keep the TV awake without keeping my finger on the manual button. But the instant I pause or hit a dead end in the user interface, instance reboot. This same, "keep it busy" method works if I cycle through menus using the power button instead of the remote.

The TV is probably going back tomorrow, but posting in case someone can think of a settings change or debugging step that might help. Hate to return it if there is a simple fix.

Bonus question: does WebOS have a log file that I can view somehow? Wonder if it would say why it is rebooting.

H
 

JayCee

Distinguished Member
Check it's not in “Store” mode.
When setting up TV's you usually get a choice of “Home” or “Store” mode.
Other than that I would suspect a hardware fault with the aforementioned power button.
 

BigH29

Member
Check it's not in “Store” mode.
When setting up TV's you usually get a choice of “Home” or “Store” mode.
Other than that I would suspect a hardware fault with the aforementioned power button.

Thanks, but that is one of the things I checked. It was in Home mode after the factory reset. Not sure what it was before that. As soon as I learned the finger trick, I went straight to the factory reset.

update: I put the TV back into store mode to see if that mattered. Same reboot behavior.

H
 
Last edited:

Clem_Dye

Distinguished Member
Check the power lead, disconnect any devices attached to it. Try a full factory reset, but if they don’t help it’s time for it to go back to the store. Perhaps it got damaged in transit by the power lead being left in situ.
 

BigH29

Member
Took a video to show what is happening. Note that I am not pressing that button, only touching it lightly.

tv360x240.gif
 
Last edited:

The latest video from AVForums

Podcast: LG C1 OLED + JBL Synthesis SDR-35 First Thoughts, plus TV Show & Disc Reviews & more
Subscribe to our YouTube channel
Support AVForums with Patreon

Top Bottom