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

[budwich]

In my limited time working with TVs to date, I have been successful at saving or repairing, a sharp 70 aquos, samsung 61 rptv, sharp 42 lcd, and a sony 46 in lcd.
Recently, a 50 plasma was dropped off... recovered from recycle.

I thought I would give it a try but am somewhat scared by the potential for disaster if "things" are not done right (ie. powering with certain cards unplugged, shorts on cards causing issues for replacement card "pairs", etc).

Anyways, as usual, I don't move fast but one of my big concerns is:

Can a plasma be worked / repaired / power while it lies face down on the work area or with this be an issue?

Pictures in some of the PDF's posted in a few threads post on here appear to mostly show a "stand based set". Hence, my concern. It probably a silly concern but better safe than sorry is my usual approach.

Thanks for any guidance on this. The 2011 panasonic is in "shut down mode" with a solid led which from the pdf's indicates protection with the likely culprits being short ss / sc boards having issues with Vsus/Vda/P15V.... don't see any obvious screen cracks.

Not sure how fast I can work this 50 in. as I need a helper to move it to the work area.... but it would be good to get it to its "final diagnostic position" on a first help.


Thanks again for the guidance on this new learning journey.

[freakaftr8]

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

You can lie a plasma down on its face no problem. You're not gonna have any mixture of gasses or issues like refrigerators lying on their face. That is a bold face flat out lie from people that don't understand the basic principles of how a plasma TV operates.

Now it's this TV should have some kind of a flashing code. Do you hear any relays click inside the power supply when you press the power button? Does the power led come on when you press the power button?

[budwich]

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

Phew... :-)

There is no flash codes. Based my quick read of the 2011 panasonic FHD techical guide posted in a thread in the forum, on the "new model", the "sos detection" shuts down and the power led stays on.... which is what I see. I haven't listen to hear for relays quite yet.

[budwich]

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

Not sure if I am doing things right, but I don't hear much / anything by just plugging in the cord. Once I press the power button, I think I hear a very slight click of a "solid state" relay (maybe). This results in the led coming on and staying solid. IF I hold the power button down for a bit (5 seconds), then the led begins to flash and the count is 14... is this caused in response to the shut down which then makes no F15V or is this the actual error code that started the shutdown in the first place? The troubleshooting guide doesn't leave much to the "imagination"... two paths, either the P board or the A board. :-( or maybe :-) if those can be had for "cheap".

[martino]

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

Be a great help if you state model number

[budwich]

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

Sorry... I was just over whelm by the readings of "plasma"... :-)

Its a tcp50s30. Based on the observations that I just saw and more readings around that, it appears that this thread is my guide once I get at the guts.
https://www.badcaps.net/forum/showthread.php?t=42430

Hopefully, its not a "dead panel"... but that probably a likely reason it headed to the recycle bin... my fingers are crossed that the person might have been just not bothered to do much once someone told them how much it might be to get fixed.... maybe.

[maxvalutech]

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

As an older guy I just find it easier to work on the larger sets with them standing up. First it saves the backbone of the tech from aches and I can sit in a chair behind them and work easily - a mirror set up so panel can be seen also helps.

[martino]

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

Very common fault on those,the screws that hold the board to the chassis come loose,therefore losing the ground and blowing up. Check those igbt's for shorts.
Link below is where you can buy a repair kit


http://www.shopjimmy.com/panasonic-t...-tc-p50s30.htm

[budwich]

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

Thanks... hopefully its not the panel. Is there a specific "in circuit test" for those devices?

My "work surface" is actually a "bar counter top" so when its not being used for doing "hobby things", its got a few "bottles" on it. :-) The problem that I have working with it upright, is I am always afraid that I may push to hard trying to get something off / out, and the set tumbles over before I can stop it. Anyways, I am glad it can be worked flat as it is easier to pull stuff off if need be.

[freakaftr8]

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

You'll have power cables going from a power supply to each sustain board the one on the left is called the SC board the 1 on the right is the SS.

Both of these boards you will have a power LED indicator that lights up green letting you know that VS voltage is going to the boards. Do you see a green light light up when you have the power button on these boards

[martino]

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

First unplug connector sc2 at the ymain board,measure the pins on the connector on the board,see if they are close to zero ohm. If it is,bingo,get the kit
Watch the video in that link,you will see which components they are,measure those from the tab to the legs,same thing,shorted means fubar.

[budwich]

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

I am still at my "waiting for helper" mode.

BUT.... Martino, I did look at the link that you posted for the possible parts.
Couple questions... the picture of the parts at the top of the page shows 6 semiconductor components and 4 resistors while the listing near the video indicators ONLY 4 semiconductor components. Which is right?

Further, I am probably screwed at this point of time as I don't have a hot air soldering station, only a regular soldering station (with temperature control). :-( It would appear that I might have invest in this area which means a "slow trip from china" maybe as this hobby doesn't get funded much. :-)

[martino]

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

2 out of the 6 in the picture are diodes. same housing,different component. Hence why the two are off to one side.

ps,a paint stripper hot air gun works too,cheap at princess auto

very similar repair,with paint stripper:
https://www.youtube.com/watch?v=uIyHr13b5w8&t=5s

[RJARRRPCGP]

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

Not sure if I am doing things right, but I don't hear much / anything by just plugging in the cord. Once I press the power button, I think I hear a very slight click of a "solid state" relay (maybe). This results in the led coming on and staying solid. IF I hold the power button down for a bit (5 seconds), then the led begins to flash and the count is 14... is this caused in response to the shut down which then makes no F15V or is this the actual error code that started the shutdown in the first place? The troubleshooting guide doesn't leave much to the "imagination"... two paths, either the P board or the A board. :-( or maybe :-) if those can be had for "cheap".

Don't a lot of TVs with a missing 15V rail or PSU problem, give 2 blinks?

[budwich]

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

thanks again...
wow that video is "scary" for me, but I do have a heat gun as I have built guitars in the past and used the heat gun to bend the sides... :-)

I guess my last question is: is there an "in circuit test" for those igbt to see which are bad or did they all go bad? My "help" should be here shortly to get the thing up on the bench.

[neilc6]

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

My limited experience with plasmas is when those IGBT transistors short, they will drive the supplying voltage to zero causing the power supply to shut down. You can narrow down the board that is shorted by unplugging them and also measuring the input resistance between the supply input and ground to see if there is a short on that individual board. Then narrow down by checking each diode and transistor.

[freakaftr8]

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

It's probably the SC board. This sounds like the tc-p55st30 just repaired. Shorted SC board. Usually 1st thing I do before I even power the TV up again with the back ot is pull both connectors from the power supply and measure the ohms resistance reading between the white and the blue wires Period from there I disconnect the bad board connect the good board and then attempt to power up and see if VS voltage comes alive.

[budwich]

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

Got on the bench, back off. Its dirty... not sure if that was from where was recently (recycle) or where it spent its service life. Nothing obviously burnt or otherwise.

OK. Following the first thread that I posted, IF I unplug the SC board from the power board and power up, I get a code 7. Measuring the resistance at the connector of the board, shows its a short. :-( ... Good I guess.

Question: in the other thread, it mentions doing a "quick check" of resistance to the Vf ground on the ribbon cables to the panel to see if perhaps the panel connections have a problem. Not sure that I understand what the check means and where those "points of interest" are.

[budwich]

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

It's probably the SC board. This sounds like the tc-p55st30 just repaired. Shorted SC board. Usually 1st thing I do before I even power the TV up again with the back ot is pull both connectors from the power supply and measure the ohms resistance reading between the white and the blue wires Period from there I disconnect the bad board connect the good board and then attempt to power up and see if VS voltage comes alive.

OK... I think I understand, you are checking the power supply line side of the disconnected cable... hoping that the power supply will at least provide some powering there before any shut down. Right?

[budwich]

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

this is a picture of the back of the set with the sc cable disconnected. I don't see any blue and white wires.