whole new repair / learning world... plasma! Yikes!

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

checked the suggested components for shorts and diode check the IC according to table. Found nothing wrong. :-( The "towel is in the air"....

[foxyUK]

Re: whole new repair / learning world... plasma! Yikes!

checked the suggested components for shorts and diode check the IC according to table. Found nothing wrong. :-( The "towel is in the air"....

one more thought... DG302s seem to go 'bad' without going short, so can be harder to spot. The checks on Q531 don't include pins 1-4, but a resistance check here or across R532 should be 47k. If it's low, the DGs could be bad. It's a regular fail on the 42" but I haven't seen it on my 50" repairs.

[tom66]

Re: whole new repair / learning world... plasma! Yikes!

I was looking at getting one of those "far east" digital "modules" that are "standalone". Cheap ones can be had but most are only single channel and 10M. As a DIY hobby guy who does really get "dirty" much, it is hard to justify putting more in as the hobby is "sunsetting". Basically, the opportunities are only when I come across something different / interesting that cost nothing but time to look at and maybe save from the landfill.

I will likely look for a used card to see if I can get this set up or at least see what the difference is between it and a "tested card" (ie. so the listing says). :-)

IMO those aren't good enough - you need a sample rate of minimum 100MSa/s and ideally 500MSa/s

An old HP/Agilent digital scope may be a worthwhile investment, or a DS1054Z is around $400 new.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

IMO those aren't good enough - you need a sample rate of minimum 100MSa/s and ideally 500MSa/s

An old HP/Agilent digital scope may be a worthwhile investment, or a DS1054Z is around $400 new.

Thanks for the guidance on this as I know little about scope specs other than "features" and "bandwidth". This is a hobby for my "fixed income" self so it is unlikely that the budget (or the keeper... :-) ) would have the bandwidth in it to allow that amount of expenditure. But one never knows what shows up on kijiji or equivalent in the area. Certainly will keep the requirements in mind when looking.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

one more thought... DG302s seem to go 'bad' without going short, so can be harder to spot. The checks on Q531 don't include pins 1-4, but a resistance check here or across R532 should be 47k. If it's low, the DGs could be bad. It's a regular fail on the 42" but I haven't seen it on my 50" repairs.

the resistance checks out at 47k (47.1k).

Anyway, I thought I would "throw in the towel" and get a replacement board (supposedly tested). Well, the "towel" might be over my head... :-)

I haven't tried the board yet as I have some issues that I hope people can direct me on. It is some what related to another thread that I posted a question about "versioning" of sc cards.

My old card is tnpa535153 AM while the replacement is tnpa5351 AF (the seller also lists "AJ" but there are no marks on it for that version and he indicated that the AM and AF/AJ were the same just different manufacturer locations... :-) ).

Now that I have the cards in my hand. There are some differences and that's where I sit now... do these make any difference? and do they matter... ie. will the card work anyways?

No sure whether I should do the discussion under this thread or the other which is kind of "dead" at the moment with no responses.

From a "first look" it appears there are some smd caps in a few places on the AM and not there on the AF board along with the main MID voltage caps being labelled different. I haven't checked / compared all the components but they look the same.

So I am now kind of "stuck" so to speak. Will this board work as is or will it blow up putting me back a square one? If I try to modify the replacement board then I am "on my own" in terms of "owning the problem / board" if it doesn't work either because the "tested" qualifier was not "accurate" and / or my soldering / transfer work was not up to "quality" for the job.

Lastly are there other components that I need to look closer at / focus on in the boards?

[foxyUK]

Re: whole new repair / learning world... plasma! Yikes!

the resistance checks out at 47k (47.1k).

Anyway, I thought I would "throw in the towel" and get a replacement board (supposedly tested). Well, the "towel" might be over my head... :-)

I haven't tried the board yet as I have some issues that I hope people can direct me on. It is some what related to another thread that I posted a question about "versioning" of sc cards.

My old card is tnpa535153 AM while the replacement is tnpa5351 AF (the seller also lists "AJ" but there are no marks on it for that version and he indicated that the AM and AF/AJ were the same just different manufacturer locations... :-) ).

Now that I have the cards in my hand. There are some differences and that's where I sit now... do these make any difference? and do they matter... ie. will the card work anyways?

No sure whether I should do the discussion under this thread or the other which is kind of "dead" at the moment with no responses.

From a "first look" it appears there are some smd caps in a few places on the AM and not there on the AF board along with the main MID voltage caps being labelled different. I haven't checked / compared all the components but they look the same.

So I am now kind of "stuck" so to speak. Will this board work as is or will it blow up putting me back a square one? If I try to modify the replacement board then I am "on my own" in terms of "owning the problem / board" if it doesn't work either because the "tested" qualifier was not "accurate" and / or my soldering / transfer work was not up to "quality" for the job.

Lastly are there other components that I need to look closer at / focus on in the boards?

Part of the discussion towards the end of the item linked below notes that the different versions are 'tuned' to the specifics of the display panel, so I guess you would at least need to establish if the replacement board came from a 50" TV. Looks to be difficult to find specifics.
https://alpengeist-tvrepair.blogspot...panasonic.html

[tom66]

Re: whole new repair / learning world... plasma! Yikes!

I think those part changes are so minor nothing bad will happen. Most likely it's a later revision of the board. It doesn't indicate a manufacturing location, seller is talking crap. Big ones to look out for are ERC inductors/capacitors, transistor count, and input cap size -- all look similar or identical to me.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

The parts list for the set doesn't show / list any parts for the "missing smd caps" (ie. the ones not on the AF baord)... not sure why that would be yet they are "stamped" on the board so the design must have known about them potentially there. The seller replied that the board useable and to go ahead and test / use it in the set.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

Did the "short SC50 connector" test with the new board installed. Set (LED) stays on with no flashing. I guess that means the old board still has an issue as suggested herein. I haven't tried the "full test" yet as I am still checking some voltages to get a "baseline" perhaps for my other board to see if I can determine the "difference" in the future... maybe.

Hopefully, the sd/su boards are not an issue.

A little testing of the MID voltage "characteristic"... watching the meter during power up, the MID voltage appears to the start at about 200v then drop to around 100-120 ( hard to tell on the digits), then ultimately rest at about 71v. From what I can remember from the old board, the second "drop" doesn't happen so something in its "switching" doesn't occur resulting in a higher MID voltage than allowed and hence the code 6 flashing.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

So the set is now working. The picture is so so as the "mosquito noise" seems very "heavy" compared to my 50 in samsung plasma that is of the same vintage (ie. 2010/2011). Not sure whether that may be the board or just settings on this set. I haven't dug into much yet.

Thanks to the forum for the help on this lllloooonnnngggg journey. Somewhat disappointed that I wasn't successful at fixing the original board but glad that the set has been saved from the scrap heap. Learned quite a bit along the way with respect to plasma versus LCD so that is good.

Hopefully, I can tune the set a bit better to improve the display.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

not out of the woods quite yet... :-(

so I can feed an hdmi signal from a computer into any of the inputs. Works fine. But it appears that a "normal signal" from a disc player doesn't "connect"... "no signal". Potentially either a cable issue (tried two other cables that work with other sets / devices), possibly a "hot detect issue" or maybe a hdmi handshake issue (hdcp or otherwise).

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

looks like the hdmi connector on the BR player has some issue... works with the samsung but doesn't work with a "saved" sony (tabs removed) and not with the panasonic (even though it did prior to the second blow up of the sc board).

Further, I did a few adjustments, mostly just changing the picture mode from "standard" to anything else reduced the mosquito noise along a few other settings and the set looks pretty good. I haven't tried to look at the hours it has on the panel but hopefully there aren't many.

[jjanssen7]

Re: whole new repair / learning world... plasma! Yikes!

Does that model have Energy Saver mode or something? I find that setting has lots of picture noise. Also, it's a basic thing and it sound like you are more experienced, but did you confirm voltages with the panel sticker?

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

thanks. eco mode is turned off. I didn't check voltages on the sticker... :-( However, the mosquito noise is basically gone now that I have change from "standard" picture mode to cinema / custom modes and adjusted things like contrast, brightness, and sharpness. Not sure why standard is so dramatic in the "noise domain" as I didn't compare all the settings but even just using the "defaults" of each, there is a significant difference in standard versus the rest. You would think that it would be the other way around.

Anyways, the tv is pretty good for a 7 year old dumpster model.

Related to the voltages, there appears to be a bit of image retention even after 5 to 10 minutes of static images. A "wipe" does remove them but perhaps some of the voltages are not quite correct. Not sure, I want to play with any thing quite yet as I have no experience in the plasma area and the set currently is buttoned up and upright (need help to get it back on the bench area).

[Moreno83]

Re: whole new repair / learning world... plasma! Yikes!

Goodjob that you fixed the tv. Dont bother repairing the old board , it had to endure to many bangs because of the fake parts.... Only do it if you want to repair it using the schematics of the SC board and have the time/parts.

The moquito noise can be a voltage issue. In europe the Vsus is around 216V with 230V input from mains.
The startup on V-SUS is 207V and after the check on the sc/su/sd boars it goes up to 215v.
If the voltage is to low or to high you will see the sparkling , however there IS always plasma dithering.

Dont forget to tighten ALL screws because also the lower c boards and ss board will have loose screws.

Enjoy your tv!

[foxyUK]

Re: whole new repair / learning world... plasma! Yikes!

If it's similar to the UK ST and above models, there is access through the software service mode to 'high' and 'low' Vsus settings, and a recommendation to check which is appropriate after a board change. You can also find panel hours via the same route.
For whatever silly reason, the key presses to enter service mode, at least in the UK, are not those shown in the manual! (they take you to the self-check screen instead).

See this great post by Tom66 for service menu usage (copy it!!!) and also hours usage.

https://www.badcaps.net/forum/showth...sor#post760122

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

thanks... I too did the vol - with power up and got to the self check mode.... not much there... not even sure the checksum is done... it read 00.

Anyways, I tuned the picture with the wow disc and its pretty good for my old eyes.... and maybe better than the samsung which is a low / middle end plasma model of the same size.

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

checked the hours of use / on in the service menu (thanks for the post link).
the sets got 20825 hours on it... so it ain't "unused". Hopefully, the black level "clock" / adjustment hasn't been invoked too much. Need to read about this as I don't think my samsung plasma does any of this "auto adjustment".

[tom66]

Re: whole new repair / learning world... plasma! Yikes!

Turn off all the picture enhancement settings - they're rubbish.
Dithering is reduced in Cinema mode - considerably - for very slightly increased flicker (virtually unnoticeable)

[budwich]

Re: whole new repair / learning world... plasma! Yikes!

yep, that's all my displays are setup. Based on a quick read of the internet, it appears that panasonic changed the "black level compensation design" in 2011 and beyond to not do any "voltage change" as the panel materials are a "better composition" that don't "age" as in the earlier years. So hopefully, nothing to worry about.