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Myth-connected TV does not reliably wake from standby #325

Open Jpilk opened 3 years ago

Jpilk commented 3 years ago

What steps will reproduce the bug?

This has already been aired on the mythtv-users list, and dismissed as a coincidence - but the problem persists and would be serious in a family situation, so I'll go on. I think there is a connection to issue #299. I had other strange events at the same time which were traced to an unexplained update in the UPnP section of ~/.mythtv/conf.xml and have not happened again. https://github.com/MythTV/mythtv/commit/e787645fd974bbed6b02ed45ae3530477bb49c58#comments https://github.com/MythTV/mythtv/commit/10b5291b832bc89ce726c5b53ac87ef738c2c3cd#comments

I have a Panasonic TV, model TX-L32E5B, bought in 2012, which still meets my needs. It has HDMI and ethernet connections to several MythTV boxes and a FireTVstick 4K. Shortly after a CEC-related commit on 4 Feb 2021 the TV could not be woken from its normal standby state with its remote control. The LED on the TV will flash, maybe red, maybe green, but often there is no other visible response. Mythfrontend settings has a 'CEC off' option, but its state doesn't seem to affect matters.

Internet searches found several 'guaranteed' cures for this. I still have not found something that works reliably; the best seems to be to switch off 'at the wall' for at least several minutes and then power-up while the power button on the remote is pressed for several seconds.

A quote from the TV Handbook:

VIERA Link "HDAVI Control (tm)", based on the control functions provided by HDMI which is an industry standard known as HDMI CEC (Consumer Electronics Control) is a unique function that we have developed and added. As such, its operation with other manufacturers' equipment that supports HDMI CEC cannot be guaranteed.

Once the TV has been successfully woken everything works as normal. After it enters standby mode, normally by the remote power button but alternatively because no buttons have been pressed for some time, all bets are off.

How often does it reproduce? Is there a required condition?

What is the expected behaviour?

What do you see instead?

Additional information

Jpilk commented 3 years ago

To continue... Waking it up took a lot of quasi-random button pushing and power-cycling again, but I now find that enabling Viera Tools ( from the Panasonic remote ) allows it to control the Firestick, with Mythfrontend and leanfront as well as the Firestick native apps. The libcec webpage has some Panasonic-specific stuff too, although that hasn't worked yet for me.

Jpilk commented 3 years ago

At present this is far from user-friendly, but with the TV's Viera tools having been activated its wake-from-standby now seems less likely to fail, using the power-on button on the Firestick's remote, perhaps interleaved with its twin on the TV's remote. The Firestick menu has sections for Equipment Control, Remotes, Preferences and more. Menu operations in leanfront using the TV remote are more sluggish than with its own, and the input is identified as EC/HDMI rather than HDMIn, n=1,2,3 or 4. No doubt Alexa wants to be involved too.

bennettpeter commented 3 years ago

My Vizio TV used to be unable to power on via remote or the TV power button. This used to happen about once per week. The solution was to unplug it at the wall and plug in again. Eventually this problem went away. I have noticed the TV doing updates and also I have switched from using mythfrontend on Linux to leanfront on a fire stick. So I don'y know what fixed it

My suggestion - put a time switch on the wall to power the TV off for 1 minute and on again, once per day at a time you are not using it.

Jpilk commented 3 years ago

There has not been any real change. I have been able to wake the TV without unplugging or pushing buttons hidden round the back, by using only the power buttons on the remotes of the TV and/or Firestick. Just unplugging, as Peter suggested, seems less effective.

I have asked both the 'Which' and Panasonic teams for suggestions; they have been responsive but had nothing more than the website that I had already seen:

https://support-uk.panasonic.eu/app/answers/detail/a_id/4410/~/why-cant-i-switch-my-tv-on-from-standby%3F

So the suggested cures seem at present to be no more certain and more inconvenient than what I have. I'll stick with it...

Jpilk commented 3 years ago

That was then: an inconvenience. After an auto-update of my FireTVstick 4K in April and a 'trial' change in its 'Devices Control' menu I was not able to get any useful response from the TV. Pressing the remote's ON button and switching ON 'at the wall' changes the LED from red to flashing green, and the flash rate increases when buttons on the remote are pressed, suggesting that some magic combination might work; but I never found one and the screen has remained black. The LED reverts to red after about a minute.

The Panasonic 'chat' helpline has told me that I cannot perform a factory reset of the TV if the screen is black. They suggested contacting an authorised repairer or offered a discount on a new TV. Given the age of the TV, a paid repair seems unlikely to make financial sense.

I have now replaced that TV with another of the same model that I had elsewhere, and can use it with MythTV via DLNA. I have not yet tried HDMI connections, either from BE/FE or Firestick, because it seems likely that some unknown CEC misconfiguration caused the 'irreversible' problem and might also affect the second TV; or perhaps it's hardware...

I suspect that this sort of thing is industry-wide and not specific to Panasonic - if it breaks, get a new one.

I would still like to get the first TV working again. Suggestions welcome.

bennettpeter commented 3 years ago

If you unplug everything from the TV HDMI input is it still dead? I am thinking perhaps it had its HDCP keys withdrawn? Apparently any device can send a message to a TV withdrawing its keys and disabling HDCP for ever after that. I had an experience that suggested this happened on another TV (Mitsubishi) a long time ago. It would work fine connected to HDMI from a computer running Linux, but connecting to a DVD player or blue ray player gave only a black screen, although those players worked on other systems.

Jpilk commented 3 years ago

Interesting, and thanks, but probably not my problem. TV1 still won't wake after days off-power and with all inputs (including the OTA antenna) unplugged. The only hopeful activity seems to be the green flashing LED and an occasional 'trying to connect' thump from the audio system connected via the headphone socket. I set up a PIN long ago and wondered if all the flashing wanted that, but it didn't help.

The biggest worry is that any replacement TV could be affected in the same way, with only any guarantee that it might have as cover.

kmdewaal commented 3 years ago

A long shot, but if your TV can be software updated via an USB stick you could try putting in a stick with the latest firmware and then powering up and see what happens. Your green flashing LED shows that some part is working but this could be a very small part. The TV chips I have worked on had a separate 8-bit 8051 processor for the IR and the LEDs and this processor decided to boot up the main processor that ran Linux. Also the power on/off switch is only attached to an I/O pin of that 8-bit processor instead of switching the real power. That is why unplugging makes a difference. My guess is that your flash memory has become corrupt. This can be worn-out or it can be because of e.g. incorrectly handled EIT as suggested by your weblink. Or by CEC handling code of course. If the problem is caused by software then your second Panasonic will also be bricked if you use it in the same way. But if the problems are caused by flash memory wear then there could be a few years of life left in your second TV. Something else: if your TV is one that has a RS232 control port you can possibly do interesting things with that. And as a final thought, TV's have become a lot cheaper over the last ten years.... and are all 4k now.... and use less energy....

On Tue, 11 May 2021 at 16:21, Jpilk @.***> wrote:

Interesting, and thanks, but probably not my problem. TV1 still won't wake after days off-power and with all inputs (including the OTA antenna) unplugged. The only hopeful activity seems to be the green flashing LED and an occasional 'trying to connect' thump from the audio system connected via the headphone socket. I set up a PIN long ago and wondered if all the flashing wanted that, but it didn't help.

The biggest worry is that any replacement TV could be affected in the same way, with only any guarantee that it might have as cover.

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/MythTV/mythtv/issues/325#issuecomment-838564744, or unsubscribe https://github.com/notifications/unsubscribe-auth/ACQBJGEN3PFLGXBZ2MVKT5TTNE4QDANCNFSM4YWV5PTA .

Jpilk commented 3 years ago

Hi Klaas: Thank you for the background info and suggestions. All good stuff but I doubt that I could apply much of it. :-)

FWIW the handbook tells me that LGPL source code is 'freely available' at http://www.am-linux.jp/dl/EUIDTV12/, but Firefox says that is 'taking too long to respond'. And there's lots of non-LGPL code too, including M$ DRM

Jpilk commented 3 years ago

Just in case anyone else sees something like this I should perhaps report that I eventually connected my second example of the 'same' 2012 model Panasonic TV and it worked - for a few weeks. I could watch OTA-direct, or mythtv by HDMI, DLNA or leanfront on a FireTVstick 4K.

All looked good with the devel/http builds. But then that TV died too, and now neither will boot to give any on-screen display. I have located and downloaded the 77 MB latest firmware but the loading instructions seem to expect a working screen - and a larger SD card than I have lying around.

I've also been looking at current TVs, of course, but no decision as yet. I was using the earphone socket to drive vintage stereo. Bluetooth now?