Weird TV Glitch? - Page 1
Forum section: electronics / general

author: RandyDarkshade
author_rank: Contributor
timestamp: August 19, 2017, 05:56:14 pm
content: I leave my TV on stand by all the time. I have owned it for about a year and a half. It's a samsung LCD. However last night it....turned on by itself. I have been told that sometimes TV's do this when on stand by, is this true? is it a weird phenomenon? A glitch? If so what would cause it? Or do I have ghosts? lol

author: StillTrying
author_rank: Super Contributor
timestamp: August 19, 2017, 06:55:54 pm
content: Do you use the TV's program guide, ...if you've accidentally set a program reminder...

author: Zero999
author_rank: Super Contributor
timestamp: August 19, 2017, 08:04:18 pm
content: It might also be infra red from LED lamps or fluorescent lamps with electronic ballasts, which switch at a similar frequency to TV remotes

author: RandyDarkshade
author_rank: Contributor
timestamp: August 19, 2017, 09:05:31 pm
content: I don't use the TV's built in TV programmer. There wasn't any other Infra red devices active or LED lights, I was trying to sleep and I turn everything off at night.

author: Augustus
author_rank: Regular Contributor
timestamp: August 19, 2017, 09:17:00 pm
content: Neighbours kids, armed with a high power tv-b-gone or universal remote, are playing a prank on you

author: Ampera
author_rank: Super Contributor
timestamp: August 19, 2017, 09:31:50 pm
content: It could seriously be anything. IR radiation is incredibly common. Even humans and other animals emit some. I wouldn't worry about it unless it continues to happen.

author: Ian.M
author_rank: Super Contributor
timestamp: August 19, 2017, 10:35:37 pm
content: The three letter agency guys switched it on remotely to update its mind control firmware . . .More seriously, standby in most modern remote controlled devices is usually handled by a MCU that also decodes the IR commands and monitors front panel buttons. If the mains power is interrupted just long enough to glitch the standby supply to the MCU, its state could be corrupted and it could be fooled into thinking it should be on. Its pretty rare as a longer power dropout would reset it and any sane design would come back up in standby to minimise the annoyance and risk of damage if the interruption is rapidly repeated, and a shorter dropout wouldn't glitch the standby supply rail enough to matter. If it was common, any reputable brand would have designed it out . . . .

author: Zero999
author_rank: Super Contributor
timestamp: August 19, 2017, 10:44:42 pm
content: Quote from: TwoOfFive on August 19, 2017, 09:31:50 pmThat's true, but the peak wavelength of IR emitted by a human is much longer than that used by a TV remote (9.5µm, as opposed to 950nm) and it isn't modulated at a high frequency.

author: BrianHG
author_rank: Super Contributor
timestamp: August 20, 2017, 12:15:44 am
content: Even though the IR receiver is tuned for a something like 38Khz-48Khz modulated IR optical signal at around 940nm, the internal amplifier demodulator has such a high signal gain, it is sensitive to many random EMI signals. This is why many of these IR receivers are encased in a tiny shielded metal case with a window opening for the IR photo diode. Usually, checksums in the IR codes would prevent the TV's MCU from accidentally interpreting the occasional glitch as a command. You may have witnessed a fluke, or if you have a neighbor with some new RF transmitting gadget or in the line of sight of a new cell tower broadcast, this may begin to happen on a regular basis.

author: Ampera
author_rank: Super Contributor
timestamp: August 20, 2017, 12:40:44 am
content: Quote from: Hero999 on August 19, 2017, 10:44:42 pmAware of that. The purpose of my stating that various animals emit IR was just to show that IR can come from almost anything. I never said it was the cause.

author: cdev
author_rank: Super Contributor
timestamp: August 20, 2017, 02:04:08 am
content: I also have a (rarely used now) Samsung LCD TV.Yesterday, for the first time ever, it turned itself on. Since the last time it was on it was acting as an HDMI monitor for my RPI, it was seeking its input. I am not kidding. The remote was in its drawer.Just another data point in this matter.Quote from: RandyDarkshade onTodayat 11:56:14

author: denverpilot
author_rank: Regular Contributor
timestamp: August 20, 2017, 03:52:41 am
content: Is it hooked to the Internet? ("Smart TV")Most Samsung TVs that are, do automatic updates late at night in whatever time zone they've decided they're in, or were programmed with.I wouldn't put it past a flawed software update to reset the "power is on" memory location after an automated reboot, for example.Just another option in the long list of things that could "turn on" something that is never really off.

author: Muttley Snickers
author_rank: Unknown
timestamp: August 20, 2017, 03:53:40 am
content: It could be a bug, seriously a bug like with hairy legs and all that.

author: Brumby
author_rank: Unknown
timestamp: August 20, 2017, 04:11:42 am
content: I cannot see it being a random IR signal received. Just too much 'coincidence' needed to get through detection and decoding. Way too much IMHO.I'd go for a power line issue as mentioned above - or something akin to "wake on ..." whatever signal avenues are available.Somebody beaming a remote through a window as a prank is also a possibility. (With the wavelengths being used, this does work. Just tested it.)

author: cdev
author_rank: Super Contributor
timestamp: August 20, 2017, 05:20:21 am
content: My TV is not hooked up to the internet nor is it hooked up to the cableIts used as a monitor... a "vessel" for the dreams of others.

author: denverpilot
author_rank: Regular Contributor
timestamp: August 20, 2017, 06:34:56 am
content: Quote from: cdev on August 20, 2017, 05:20:21 amFair 'nuff.Reason I mentioned it is I've found my Samsung on once, unexpectedly, along with new firmware in it.It's connected to the Interwebz so the spy agencies can know when I'm watching YouTube videos from Dave on it via screencasting tech of various flavors or one of the streaming boxes, of course.That way they know I'm not building something nefarious in my electronics room and ham shack. I try to make their jobs as easy as possible.But I'm guessing my "mystery on" had more to do with crappy rural mains power than anything. I'm amazed my power co-op doesn't blow up more of my gear.Waking up to the thumping of the subwoofer going on and off at 2AM when they're having a particularly bad night in snowstorms, is always a treat. And something to thank the amp designer for if I ever meet him or her. Haha.

author: Naguissa
author_rank: Regular Contributor
timestamp: August 20, 2017, 06:53:58 am
content: I've read several Samsung-specific cases:- Most probable: power supply starting to fail.- Maybe: Power glitch on mains.- Less probable: an hdmi connected device, but you have been suspecting about this if there was a new device connected.If it starts repeating more often that will be 1st option.Enviado desde mi Jolla mediante Tapatalk

author: JohnPen
author_rank: Regular Contributor
timestamp: August 20, 2017, 08:22:00 am
content: There was a similar problem with Panasonic TVs some years ago. It turned out to be caused by poor quality electrolytics on the standby circuitry board/area. The capacitors usually started to bulge at the ends. They were typically a couple of hundred uFd ~25 volt so called 105 degree rated. Replacement of those 2 capacitor, if I remember correctly, cleared the problem. Maybe this is the same problem and the standby circuitry is located in a hot area of the TV.

author: electr_peter
author_rank: Unknown
timestamp: August 20, 2017, 05:42:40 pm
content: Phillips LED TV (dumb version with no internet) turned on randomly ~5 times in last 6-12 months. It happened at night, day, morning, evening. My guess it is either internal reset (because SW crashes and resets) or RF/light interference from outside.

author: tom66
author_rank: Super Contributor
timestamp: August 20, 2017, 06:53:29 pm
content: Does it have touch panel controls? (Capsense, no physical button)Samsung has notoriously bad touch panel controls on some of their TVs, mostly the ones around 2008-2011.They will sometimes pick up random touches causing channel changes, and possible could turn the TV on, though I've not seen that one before.

author: Cerebus
author_rank: Super Contributor
timestamp: August 20, 2017, 10:22:52 pm
content: Quote from: Hero999 on August 19, 2017, 10:44:42 pmIt is if you're anywhere near a UBeamTMremote charger.

author: Halcyon
author_rank: Unknown
timestamp: August 21, 2017, 02:08:07 am
content: Check what HDMI devices you have plugged in. They may be sending CEC commands to your TV to turn on. I had this same issue with a DVR which would fire up the TV every time it powered on to record a TV show. You may be able to disable CEC either on your TV or on the devices themselves.

author: CopperCone
author_rank: Super Contributor
timestamp: August 21, 2017, 06:20:56 am
content: could be a virus too.. bound to happen eventually, people will mimic CIA shit

author: FreddyVictor
author_rank: Regular Contributor
timestamp: August 21, 2017, 03:26:49 pm
content: My approx 8yr old Samsung does this occasionally, maybe updating it's firmware via over-air update maybe ?some years back it did have power supply repaired (electrolytic caps were too low a voltage), but it still does it as I noticed it on the other day.TV is not plugged into anything else

author: cdev
author_rank: Super Contributor
timestamp: August 22, 2017, 05:21:07 pm
content: I wonder, should I put a 75 ohm terminator on its input and see if it happens again ?Just kidding...

author: G7PSK
author_rank: Super Contributor
timestamp: August 22, 2017, 08:46:57 pm
content: I have a sony that switched itself on a few weeks ago, I put it down to line switching or transients, it only did it the once and we often get line switching errors that are visibly noticeable here.