HDMI Dead on Panasonic TCP50S2 Plasma TV

[Samuel M. Goldwasser]

Hi:

I have this set, about 3-1/3 years old, used lightly.

About a year ago, HDMI 2 stopped working. Yesterday, HDMI 1 and 3 died.

A Panasonic Blu-ray player connected to any of these returns U72 or U73 - "The
HDMI connection acts unusually. The connected equipment is not HDMI
compatible.".

This had been working fine. The only thing that works through HDMI now is
that the player turns on the TV and switches to the connected HDMI input,
which is blank. After a few seconds the player displays U72 or U73 but it
continues playing.

Composite, Component, and the Tuner still work.

Google returns a variety of problems with A/V inputs on Panasonic TVs
but besides replacing the "A" board ($$$ and who knows if any given version
will be compatible) or resetting to factory defaults, I haven't seen a
solution. I have umplugged the TV for a few minutes with no change.
I'm reluctant to do the Factory Reset but will try that if necessary and
there's a chance it will work.

Thanks!

--
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[John Robertson]

On 02/23/2014 10:52 AM, Samuel M. Goldwasser wrote:
> Hi:
>
> I have this set, about 3-1/3 years old, used lightly.
>
> About a year ago, HDMI 2 stopped working. Yesterday, HDMI 1 and 3 died.
>
> A Panasonic Blu-ray player connected to any of these returns U72 or U73 - "The
> HDMI connection acts unusually. The connected equipment is not HDMI
> compatible.".
>
> This had been working fine. The only thing that works through HDMI now is
> that the player turns on the TV and switches to the connected HDMI input,
> which is blank. After a few seconds the player displays U72 or U73 but it
> continues playing.
>
> Composite, Component, and the Tuner still work.
>
> Google returns a variety of problems with A/V inputs on Panasonic TVs
> but besides replacing the "A" board ($$$ and who knows if any given version
> will be compatible) or resetting to factory defaults, I haven't seen a
> solution. I have umplugged the TV for a few minutes with no change.
> I'm reluctant to do the Factory Reset but will try that if necessary and
> there's a chance it will work.
>
> Thanks!
>

Hi Sam,

Isn't this the point where you would break out your Dick Smith/Bob
Parker ESR meter and check the caps on the power supplies? When things
fail as you indicated - the problem got worse and then stopped working -
my first suspect is failing power regulation caused by bad caps...

John :-#)#

--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

[Samuel M. Goldwasser]

It may come to that. :( :) For now I've not going to do anything as
the Component Video inputs will satisfy my needs, if a bit less
conveniently.

And yes, that ESR meter is probably my single most useful piece of
test equipment after a DMM. ;-)

[mrob...@att.net]

Samuel M. Goldwasser <s...@repairfaq.org> wrote:
> The only thing that works through HDMI now is that the player turns on
> the TV and switches to the connected HDMI input, which is blank.

This is probably a function of the Consumer Electronics Control (CEC)
line on the HDMI input, which is basically an I2C bus for passing
remote-control type data around. It has its own pin on the HDMI
connector. One of the commands a source can send to a display on this
bus is "switch your input to me please". So at least *part* of the
interface is probably working.

There is a small possibility that the high-speed data lines on each HDMI
input go through some kind of fancy buffer/line receiver chip (the son
of a son of an MC1489) before going to the CPU. If there is one of
these chips per input, perhaps they are failing over time. It's
probably more common that all three HDMI inputs go into the CPU or some
other big multi-purpose chip.

Somebody (I think maybe the source, but possibly the TV) is also
supposed to provide +5 V, 50 mA on the HDMI connector. For your case,
where both ends have line power available, I don't think this power is
actually used for anything, but if it's low (power supply fault) or
getting pulled low by something (cable fault?), maybe that is detected
and is causing one end or the other to be unhappy.

If all three HDMI inputs had quit working at once I'd suspect something
like the cable (easy to fix) or the HDCP negotiation (hard to fix by
design). This may fall into the category of grandmothers and eggs, but
have you tried a different HDMI source and HDMI cable?

Matt Roberds

[Samuel M. Goldwasser]

Yes. :)

Enough is working that the BD player does turn the TV on via the HDMI
and switches the TV to that HDMI input. It's only when it goes to
paly the disc that the error is produced and no video.

Thanks for responding!

[John Robertson]

Yeah, this is sounding like bad power, it works until a larger load is
added - the DVD player...

[Michael Black]

I dragged home an Acer 19" LCD monitor a few years ago (found on a busy
downtown street, in front of a grocery store, no other garbage there).

I plugged it in, it worked, at least the Acer logo came on. I connected
to a computer (VGA, the only other connector was DVI), and it worked. So
I moved my other monitor out and put this in place. And when I left
things on, the monitor would seem to reset, certainly the Acer logo
appeared, and nothing I did would get the picture from the computer back.

So I opened it up and changed the obvious power supply electrolytics, none
were bulging.

And it worked fine after that.

Since it worked, and then reset, I would have thought some other issue was
the problem. But apparently not, so where the symptom seems to point to a
solution, it's actually misdirection.

Check the FAQ, try a different cable, try a different source, try a nother
monitor if you've got spares. That might give information that helps find
a solution.

Michael

[John-Del]

Don't bother poking around the power supply, the problem is definitely on the A main board. Take a close look into all the HDMI connectors and see if there isn't a displaced pin on even one of the inputs. One displaced pin shoved up against another can wreak havoc with the whole group of inputs.

I can't get a schematic up because Panasonic's service website has been down for some time, but older A boards used a separate HDMI select chip, which as you would imagine, would do the selection of the wanted HDMI input and funnel it out to the main IC. These are pretty tightly packed surface mount chips, but are replaceable. We see them fail most often in the summer, when lightning activity whacks these chips. It's possible yours was damaged through one port, and the chip has been limping along and finally failed.

Later Panasonics incorporated the HDMI select into the main chip directly. Since these are ball grid ICs, you're better off replacing the A board.

Before doing anything, you could try reflashing the firmware, although I've never seen this solve the problem on a Panasonic as it has for other brands.

[Mike Tomlinson]

En el artículo <uwqgkw...@repairfaq.org>, Samuel M. Goldwasser
<s...@repairfaq.org> escribió:

> It's only when it goes to
>paly the disc that the error is produced and no video.

So the TV shows the usual menus, etc. from the BD player, but only
throws an error when you try and play a disc?

Some form of weird copy protection? Tried a known working disc?

Could the TV have had an over-the0-eir software update without yo
knowing, which has broken something?

--
(\_/)
(='.'=)
(")_(")

[Mike Tomlinson]

En el artículo <alpine.LNX.2.02.1...@darkstar.example.org>
, Michael Black <et...@ncf.ca> escribió:

>Check the FAQ

Sam *wrote* the FAQ :-)

[Michael Black]

On Wed, 26 Feb 2014, Mike Tomlinson wrote:

> En el artículo <alpine.LNX.2.02.1...@darkstar.example.org>
> , Michael Black <et...@ncf.ca> escribió:
>
>> Check the FAQ
>
> Sam *wrote* the FAQ :-)
>

Which is precisely why I put it in there.

Michael

[Samuel M. Goldwasser]

Mike Tomlinson <mi...@jasper.org.uk> writes:

> En el artículo <uwqgkw...@repairfaq.org>, Samuel M. Goldwasser
> <s...@repairfaq.org> escribió:
>
> > It's only when it goes to
> >paly the disc that the error is produced and no video.
>
> So the TV shows the usual menus, etc. from the BD player, but only
> throws an error when you try and play a disc?

No, the TV shows nothing through any of the HDMI ports. But the BD player
displays an error once it starts to play. It continudes to play with the
U72 or U73 error displayed, but nothing shows up on the screen.

What it does do it automagically turn on the TV via the VIERA link through
the HDMI, so something on the HDMI is working. Just no picture.

> Some form of weird copy protection? Tried a known working disc?

This is with know working DVDs.

> Could the TV have had an over-the-eir software update without yo

> knowing, which has broken something?

Not likely. I don't think this TV can update firmware off air. There is
no Internet connection.

Thanks for your thoughts!

[Samuel M. Goldwasser]

Mike Tomlinson <mi...@jasper.org.uk> writes:

> En el artículo <alpine.LNX.2.02.1...@darkstar.example.org>
> , Michael Black <et...@ncf.ca> escribió:
>
> >Check the FAQ
>
> Sam *wrote* the FAQ :-)

:)

Too bad there isn't really anything on modern flat screen TVs in there....

[Samuel M. Goldwasser]

Yeah, actually a suggestion like that isn't silly. I often forget what's
in the FAQs! ;-)

[Michael Black]

On Wed, 26 Feb 2014, Samuel M. Goldwasser wrote:

> Mike Tomlinson <mi...@jasper.org.uk> writes:
>
>> En el artículo <alpine.LNX.2.02.1...@darkstar.example.org>
>> , Michael Black <et...@ncf.ca> escribió:
>>
>>> Check the FAQ
>>
>> Sam *wrote* the FAQ :-)
>
> :)
>
> Too bad there isn't really anything on modern flat screen TVs in there....
>

It is too bad, and I couldn't figure out how to fit that in without making
it sound negative. The FAQ is still great, except it's not kept up with
the present (or future, depending on how you look at it).

The neat thing is, LCD tv sets and monitors are so much easier to work on,
at least the boards, than in the days of CRT tv sets and monitors, where
the main board had endless wires and you had to pull out the board in
order to do any work on it. An LCD monitor has two, or maybe sometimes
just one, board, and they are so easy to remove to work on.

Michael

[John-Del]

On Wednesday, February 26, 2014 4:29:18 PM UTC-5, Samuel M. Goldwasser wrote:

But the BD player
>
> displays an error once it starts to play. It continudes to play with the
>
> U72 or U73 error displayed, but nothing shows up on the screen.

Geez Sam, did you try another DVD player or game system? You may have a bad Blu player as well as just one HDMI port inop....

I've seem a bunch of Pannys with a single bad HDMI input.

[jurb...@gmail.com]

If a firmware update is not available for it or is but doesn't fix it you need a main board.

[Michael Black]

On Wed, 26 Feb 2014, jurb...@gmail.com wrote:

> If a firmware update is not available for it or is but doesn't fix it
> you need a main board.
>

Well maybe we'll get a new Repair Brief out of this, I remember when they
were posted here. The neat things Sam would find, and then get going.

Michael

[jurb...@gmail.com]

I'm pretty sure about the signal not getting through the big damn chip. The question is whether it is a software or hardware problem. If you go to shopjimmys and look at a picture of the main board fro that model, alot of those traes from the HDMI jacks go straight to a big BGA flat thing with a heatsink. The page is here :

http://www.shopjimmy.com/panasonic-txn-a1lquus-a-board.htm

Next to each HDMI jack is a little SMD transistor, no doubt a buffer for whatever data an HDMI device wants to tell the micro. Now if plugging in a modern device (which he has) causes the set to switch to that input (which it did) and it does not produce a picture, the test is inconclusive. the IC that selects the HDMI input could simply be bad, but on the other hand it may not have neen initialized properly. this can be caused by a bad micro, or more likely corrupt data. the corrupt data can be caused by a defective EPROM.

Now actually, EPROMS don't go bad as often as the used to, and I think that shitty power supplies cause alot of data corruption. they depend on specific capacitances in electrolytics for an orderly power down sometimes, which ois shitty engineering because the never gain ESR and/or lose capacity at the same rate over time. In a three year old unit, the screwup could have happened once when turned on cold in a certain mode, or whatever. It depends on too much to be analysable effectively withoput a hell of alot of information and equipment we do not have.

If I could reverse engineer a data port on the thing and had a properly working unit, I would indeed try to load the data from the EPROM in the workiung unit into the non-working unit. I would say that most likely it would fix it.

I would then consider modifying the power supply to make a recurrance less likely. Most likely I would be forced to trust the engineers to have designed it so that a sustained Vcc or Vdd to the micro and EPROM would not damage the ports by having the other supplies slam down on the protection diodes in all the other ICs.

Of course all this is not going to happen. I've never dealt with load EPROMS manually using a PC. I know RCA's Chipper Check software has suck a function. I also know tha tin other electronic fields it is done sometimes, but they are working on expensive equipment that justifies the cost of all this horseshit. If we could get EPROM images when these sets are new, that owuld not be so bad, but where the hell are you going to find the exact same model, and I mean exact. Just because it has the same model number does not mean it is the same model. I have found this out enough times...

So we are down to replacing the board, because if it is a software problem you can change ALL the parts and not fix it. Got one someone broke in half ? go ahead and just change the EPROM. It is SMD but it's only eight pins. It is doable, even for us old guys who can't see.

But get one.

[Mike Tomlinson]

En el artículo <alpine.LNX.2.02.1...@darkstar.example.org
>, Michael Black <et...@ncf.ca> escribió:

> An LCD monitor has two, or maybe sometimes
>just one, board, and they are so easy to remove to work on.

But realistically, about the only thing you can do is replace bad caps
on the power supply board. The main boards are essentially unrepairable
with their SMD chips.

Repair is pretty much limited to complete replacement of the main board
or LCD panel, neither of which is economically viable.

[Michael Black]

Yes, but plenty are being tossed because of bad capacitors, and thus are
really easy to get going.

I'mnot seeing LCD tv sets on the sidewalk yet, but all the LCD monitors I
have have been found on the sidewalk. SOme need new capacitors. One was
a badly damaged screen, but in taking that one apart I saw how little
there was inside. SOme of the smaller ones had some damage to the screen,
but not enough to be a bother.

They are a lot more convenient to keep around than CRT monitors, so much
smaller and lighter.

Michael

[Samuel M. Goldwasser]

John-Del <ohg...@aol.com> writes:

> On Wednesday, February 26, 2014 4:29:18 PM UTC-5, Samuel M. Goldwasser wrote:
>
> But the BD player
> >
> > displays an error once it starts to play. It continudes to play with the
> >
> > U72 or U73 error displayed, but nothing shows up on the screen.
>
> Geez Sam, did you try another DVD player or game system? You may have a bad Blu player as well as just one HDMI port inop....

Yes, FIOS and Blu-ray both come up blank, though FIOS doesn't show an error.

[Samuel M. Goldwasser]

That dates us. ;( :)

Unless it gets worse, I'll just live with using Component Video.

Someone else noted how much easier it is to get to the guts of these modern
flat screen sets. That is certainly true, but balance that with the sheer
size and it becomes a pain to find a spot to even work on it!

[jurb...@gmail.com]

I built some nifty stands for that purpose. I'll find the pictures later.

[jurb...@gmail.com]

This is what you need to fix flat sets :

https://dl.dropboxusercontent.com/u/29948706/MYDC0105.JPG

In fact I'll even buildem forya, but shipping would be ridiculous. The only problem for most peope is cutting an accurate 60 degree angle. Miter saw won't do it, it takes a table saw.

Unless you want to do it freehand.

[jmry...@gmail.com]

Hi Samuel,

Did you figure out this issue in the end? I am having the same problem with my Panny TC-P50GT50...

Thanks,
Jimmy

You are welcome to email me directly at jmry...@gmail.com - thanks so much for your help. I am glad to see I'm not the only one with this issue.

[Samuel M. Goldwasser]

jmry...@gmail.com writes:

> On Thursday, February 27, 2014 at 4:21:53 PM UTC-5, Samuel M. Goldwasser wrote:
>> Michael Black <et...@ncf.ca> writes:
>>
>> > On Wed, 26 Feb 2014, jurb...@gmail.com wrote:
>> >
>> > > If a firmware update is not available for it or is but doesn't fix
>> > > it you need a main board.
>> > >
>> > Well maybe we'll get a new Repair Brief out of this, I remember when
>> > they were posted here. The neat things Sam would find, and then get
>> > going.
>>
>> That dates us. ;( :)
>>
>> Unless it gets worse, I'll just live with using Component Video.
>>
>> Someone else noted how much easier it is to get to the guts of these modern
>> flat screen sets. That is certainly true, but balance that with the sheer
>> size and it becomes a pain to find a spot to even work on it!
>>
>> --
>> sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/

> Hi Samuel,
>
> Did you figure out this issue in the end? I am having the same problem
> with my Panny TC-P50GT50...

Nah, I'm just using Component Video, sorry. :( :) One solution I've
been told is to replace the "A"? board. The cost and hassle simply
isn't worth it to me, and then have it go out again in a year!

Cheers!

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

>

[John-Del]

On Tuesday, June 30, 2015 at 4:21:41 PM UTC-4, Samuel M. Goldwasser wrote:

> > Hi Samuel,
> >
> > Did you figure out this issue in the end? I am having the same problem
> > with my Panny TC-P50GT50...
>
> Nah, I'm just using Component Video, sorry. :( :) One solution I've
> been told is to replace the "A"? board. The cost and hassle simply
> isn't worth it to me, and then have it go out again in a year!
>
> Cheers!
>

An A main will fix both TVs. Unfortunately, both of these are later versions that incorporate the HDMI receiver/select into the BABGA. No manufacturers offer BGA chips separately that I know of. In any case, difficult for the pro and almost impossible for the novice to change even if the chip was available. This leaves replacing the A board and hoping you get a good one, or use the component inputs (which is what I would do on my own TV)