Panasonic TX-40ES503B Intermittent Power On

[DanielCoffey]

We have a wall-mounted Panasonic 40" TX-40ES503B at home which we have owned since new (around four years) and it has recently become reluctant to power on via the button on the rear lower right. We would appreciate any advice please.

The symptoms are as follows...

1. Press the Power On button with a short press. This button is a momentary with a tactile "click" when pressed and when released.

Usually the TV will not power on and there is no activity. Sometimes it does power on and remains on.

2. If it did not power on, short press it again. It always powers on a second time if the two presses are reasonably close to each other (a few seconds).

3. If it did not power on the first time, a long wait (several minutes) will result once again in the fault of usually not powering on until a second press.

4. A long press-and-hold almost always turns the set on.

Are we looking at a loose or dirty button here or might there be something that is failing to initialise within a permitted time limit?

Please bear in mind that I am a home user, not a professional but am confident to build my own PCs so am prepared to replace assemblies inside a device. I do not have any ability with soldering however.

Many thanks in advance,

Daniel.

[dick_barton]

Re: Panasonic TX-40ES503B Intermittent Power On

Welcome Daniel.
Without taking voltage readings on the power supply it would be difficult to diagnose.
Also some pictures of your circuit boards could help shed light of the problem; not always but sometimes a damaged component can be spotted.

[DanielCoffey]

Re: Panasonic TX-40ES503B Intermittent Power On

I can certainly get the TV off the wall mount and the back removed. I do have a multimeter by the way and can take appropriate care with the mains voltages.

Are there any service or disassembly guides for the Panasonic ES500 series I could refer to? There are a million screw on the back as you will be aware and I don't know if any clips need to be located and pressed in.

[dick_barton]

Re: Panasonic TX-40ES503B Intermittent Power On

Start with the removing the screws and make a note of which size go where. You wouldn't wanrt to damage a board by putting a long screw back in where initially a short screw was.

Once they are all out, if there's a problem removing the back cover then I'm sure a shout here with some photos would get you some help.

Do a search on the forum under your model number and see if you can gleam any early information.

[DanielCoffey]

Re: Panasonic TX-40ES503B Intermittent Power On

Thank you - I will make an appointment to take it off the wall and have a good look. It is our only screen and taking it out of commission without making the rest of the house aware would put me in the dog house pretty quick!

I will keep a note of where the screws go and make sure I get a well lit and focused pic of the power supply board then report back.

[DanielCoffey]

Re: Panasonic TX-40ES503B Intermittent Power On

It has just done it and I have gathered more information...

1. Press Power On button
2. Front Power LED blinks green rapidly for 1s
3. Backlight comes on
4. TV turns off.

Press Power button again

5. Front Power LED blinks green rapidly for 1s
6. Backlight comes on
7. TV starts.

Does this still sound like a dirty switch? I suppose it could be treating an intermittent signal from the switch as a command to turn off. I have not yet had an opportunity to open the case up.

[dick_barton]

Re: Panasonic TX-40ES503B Intermittent Power On

It doesn't sound like a faulty switch since your post above indicates that it does the same thing. ie 2 = 5, 3 = 6

Can you turn the backlights (not brightness or contrast) down as low as possible next time it comes on and see if the set will come on at switch on without failure.

Have you the latest firmware update
https://av.jpn.support.panasonic.com...uk_cis_01.html

[DanielCoffey]

Re: Panasonic TX-40ES503B Intermittent Power On

The firmware was three years out of date (I think I checked it when we first bought it) so now it is fully up to date without issues.

I will check the power on behaviour over the next couple of days then if it still misbehaves I'll take it down and remove the wall mount.

I can see from the back of the TV that there is a clamshell cover over the innards on the lower 2/3 of the back. ALL the screws that are visible are on that clamshell so the boards will presumably be underneath that.

[dick_barton]

Re: Panasonic TX-40ES503B Intermittent Power On

If successful don't forget to let us know.

[DanielCoffey]

Re: Panasonic TX-40ES503B Intermittent Power On

After the firmware update yesterday it behaved itself for the rest of the day even if I went past and turned it on and off. You know how it is... the damn things know they are being watched!

But then I caught it by surprise this morning and it actually did something different which it has not done before... it hung during its power on process, before it even managed to present its own menu.

1. Power On with "normal" press
2. Green power led rapid blinks for a bit over 1 second
3. Backlight comes on (still normal brightness)
4. Power LED goes steady green
5. Screen displays "HDMI2" in a box top left (because the AppleTV is on that connection)
6. Device freezes and no further screen changes occur even if AppleTV is manually woken by its own remote. "HDMI2" remains on screen.

The TV did not display its own menu across the top of the screen. The next step would have been to negotiate resolution and refresh via HDMI2, display its top bar then display the AppleTV client display.

I left it for 30s then powered it off via button (which worked).

On a second attempt it booted normally with no issues.

It is definitely getting opened up for inspection and photographs.

[dick_barton]

Re: Panasonic TX-40ES503B Intermittent Power On

Can you enter the service menu and do a factory reset on it.

Search the internet for the procedure for your set unless anyone on the site can tell you.

Maybe one of these https://factory-reset.com/wiki/Panasonic_Service_Menu

[DanielCoffey]

Re: Panasonic TX-40ES503B Intermittent Power On

Yes I can do that. I will take phone camera pics of the current settings before I do.

[DanielCoffey]

Re: Panasonic TX-40ES503B Intermittent Power On

I have done a System Reset on the TV. I will allow the set to lie powered off for a while then will continue to sneak up to it for an unexpected power on every once in a while to check for booting failures.

[DanielCoffey]

Re: Panasonic TX-40ES503B Intermittent Power On

OK, I have managed to replicate the hanging during boot issue where it did display the HDMI2 box. I have apparently mis-remembered the sequence as it actually progresses like this...

1. TV Powered off, AppleTV asleep
2. Press Power On button on TV
3. Green power led rapid blinks for 1-2s
4. Backlight comes on
5. Top frame of TV menu appears briefly
6. "HDMI2 Auto 16:9" displayed in box
7. Top frame of TV menu disappears
8. "HDMI2 Auto 16:9" changes to just "HDMI2"
9. No further changes for 10 seconds.

I noticed that the AppleTV was still asleep so I powered off the TV at the switch and woke the AppleTV manually using its remote.

The next power on sequence was correct...

1. TV Powered off, AppleTV AWAKE
2. Press Power On button on TV
3. Green power led rapid blinks for 1-2s
4. Backlight comes on
5. Top frame of TV menu appears briefly
6. "HDMI2 Auto 16:9" displayed in box
7. Top frame of TV menu disappears
8. "HDMI2 Auto 16:9" changes to "HDMI2 1080p 50Hz"
9. Top frame of TV menu reappears and remains for a few seconds before fading
10. Current AppleTV page displayed (varies according to what it was doing last time)

So it seems now that my problem has changed to a failure to wake the HDMI-attached device.

The cable is a very high quality one and is correctly secure at both ends.
The AppleTV is a 1080p AppleTV 4th Gen connected via LAN to my network switch. The TV is of course 1080p.

[nomoresonys]

Re: Panasonic TX-40ES503B Intermittent Power On

Do you have something else to plug in that hdmi? See if that device works right, to try to narrow the issue.

[nomoresonys]

Re: Panasonic TX-40ES503B Intermittent Power On

Did apple tv have a recent update or settings change?

[DanielCoffey]

Re: Panasonic TX-40ES503B Intermittent Power On

I don't have any other HDMI devices I am afraid but I will look at the Wake settings on the AppleTV for anything obvious. I can also see if the TV shows any issues if HDMI2 is disconnected.

[DanielCoffey]

Re: Panasonic TX-40ES503B Intermittent Power On

I have tried a different cable but the issue persists. I have tried moving between different HDMI ports on the TV too and it is completely consistent.

It is oddly one-sided too and is 100% reproducible...

Test 1 : Apple TV asleep, TV powered off.

- Power on TV, TV boots, fails to wake the AppleTV, screen stays dark with the HDMI2 box.

Test 2 : AppleTV awake, TV powered off.

- Power on TV, TV boots, AppleTV responds with 1080p, 50Hz and menu is displayed correctly.

Test 3 : AppleTV alseep, TV powered off.

- Wake AppleTV using remote, AppleTV wakes, TV remains dark of course.

Test 4 : AppleTV asleep, TV asleep.

- Wake Apple TV using remote, AppleTV wakes, TV wakes, AppleTV responds with 1080p, 50Hz and menu is displayed

In short the TV cannot wake the AppleTV but the AppleTV can wake the TV. Is it actually meant to be one-sided or should it work both ways?

[dick_barton]

Re: Panasonic TX-40ES503B Intermittent Power On

Does your computer have an HDMI output connector??

[DanielCoffey]

Re: Panasonic TX-40ES503B Intermittent Power On

Yes it does but it is a big CaseLabs case... it might be easier to lug the wall-mounted TV over there than move the PC.

At the moment I am not having any failures to boot since updating the firmware so that is a great improvement. Who knows if there were some timing margins that were relaxed in there... but I am curious as to whether the TV is sending a Wake command to the AppleTV or not. I don't have a spare one to try it on.

Are you suggesting I connect the PC to the TV as a 1080p monitor then see if it sends a wake to the PC when turned on? I would not really expect it do do that I have to be honest.

I am beginning to wonder if I have always clicked the AppleTV remote when removing it from the holser on teh back of the TV and therefore never noticed the lack of Wake from the TV to the AppleTV before.