Water inside Panasonic projection tv mystery

[Doc38343]

I have this older rear projection and it has been in DRY storage for 2 1/2 years.
I knew the local power company killed the power supply because I was watching it when it happened (surge from mains transformer blowing up)

I decided I would fix it today but low and behold there are 3 puddles of brownish water on the boards. It dripped out of the cones above that the color projectors are encased in. What the heck??? It has been dry from the time i unplugged it.

Mystery to me but i am not even sure I want to try and fix it now.

Thanks in advance but has anyone seen this before?

[goontron]

Re: Water inside Panasonic projection tv mystery

My guess is that's glycerin or Ethylene Glycol (they used both) from the projector lenses. Its reaching EOL very fast. Also, if they dump the rest, it won't come out of your carpet.

[kaboom]

Re: Water inside Panasonic projection tv mystery

It's not water.
http://opa-and-granna.blogspot.com/2...k-of-that.html

Extreme temperature swings while in storage helped force it out, but they were always leakers to begin with.

In addition to a coolant change, those boards need to be completely cleaned of the stuff. Otherwise, the power supply and deflection/HV out will burn up.

Beware that some CRT assemblies are held not with screws/springs, but torsion rods. If that's what you've got, you'll think you can open and clean the CRTs/chambers, but you'll never get them back together. The tension is too strong and jigs are required.

[Doc38343]

Re: Water inside Panasonic projection tv mystery

It's not water.
http://opa-and-granna.blogspot.com/2...k-of-that.html

Extreme temperature swings while in storage helped force it out, but they were always leakers to begin with.

In addition to a coolant change, those boards need to be completely cleaned of the stuff. Otherwise, the power supply and deflection/HV out will burn up.

Beware that some CRT assemblies are held not with screws/springs, but torsion rods. If that's what you've got, you'll think you can open and clean the CRTs/chambers, but you'll never get them back together. The tension is too strong and jigs are required.

Hey thanks to both you guys makes sense now. In my mind I would say it is nowhere near worth the trouble to repair... I will likely pull the boards for salvage, any other Ideas out there Id like to hear... the waste truck runs on thursday


Thanks
Doc

[goontron]

Re: Water inside Panasonic projection tv mystery

Hey thanks to both you guys makes sense now. In my mind I would say it is nowhere near worth the trouble to repair... I will likely pull the boards for salvage, any other Ideas out there Id like to hear... the waste truck runs on thursday


Thanks
Doc

well you could... never mind. not everybody can pull a Photon.

[Doc38343]

Re: Water inside Panasonic projection tv mystery

well you could... never mind. not everybody can pull a Photon.

Yup!!! especially me..LOL I'm way better at de-soldering and salvage! Soldering iron and air compressor and the parts literally fall out. (youtube trick I learned from a German kid and really saves the part from too much heat as well)

Seriously??? Photon???..... possible Tennessee target practice sounds way more fun!
HOLD UP! WILL PHOTONS EXPLODE WHEN SHOT?????!!!!!!!!

[stj]

Re: Water inside Panasonic projection tv mystery

why not just drain and refill the coolant?

it used to go foggy on the blue tube over time anyway.
(must be organic)

[Doc38343]

Re: Water inside Panasonic projection tv mystery

why not just drain and refill the coolant?

it used to go foggy on the blue tube over time anyway.
(must be organic)

Hey I'm game for learning and not wasting.... It was a great TV until the PCompany blew it up by overloading the transformer outside my house... they told me it was an act of God so i asked em why did they tick him off...

I thought they were razzing me... but if serious,, how can I change the coolant and where would I get it at? (I have no fears cleaning the boards in question)
At first I thought it was rat pee....

[kaboom]

Re: Water inside Panasonic projection tv mystery

why not just drain and refill the coolant?

it used to go foggy on the blue tube over time anyway.
(must be organic)

If the glycol solution sat on the boards for any length of time, as in the OP's case, I'd be concerned about the fine-pitch traces on that double-sided signal/syscon board.

The power/sweep board(s) weren't as prone to that, with their heavier traces, but they must be properly cleaned. Either in a dishwasher or a mild Simple Green solution and rinse.

Any residue is conductive, and that silicone around the CRTs' anode connections was a response to a problem. Slow weeping leaks used to make the HV short out, so the idea was to "seal" the HV away.

But the coolant still leaked on some of them. I recently gutted a Mitsubishi with better-than-average coolant retention; even so, there was evidence of very slight seepage.

I think the drip shields became mandatory by UL spec, after a number of RPTVs had (power/sweep) board fires back in the 80's.

[kaboom]

Re: Water inside Panasonic projection tv mystery

Hey I'm game for learning and not wasting.... It was a great TV until the PCompany blew it up by overloading the transformer outside my house... they told me it was an act of God so i asked em why did they tick him off...

I thought they were razzing me... but if serious,, how can I change the coolant and where would I get it at? (I have no fears cleaning the boards in question)
At first I thought it was rat pee....

Are any lights getting brighter when large, 120V loads (fridge, washing machine, window aircon, vacuum cleaner) start?

Ask neighbors if they've just had any of their electronics blow up. If the POCO transformer, or feeder/lateral/drop to your house lost the neutral, your supposed "120V" goes well above 200V! It depends on the load on each half of the secondary, and if parallel paths are present; also how "good" of a path they are.

[Doc38343]

Re: Water inside Panasonic projection tv mystery

Are any lights getting brighter when large, 120V loads (fridge, washing machine, window aircon, vacuum cleaner) start?

Ask neighbors if they've just had any of their electronics blow up. If the POCO transformer, or feeder/lateral/drop to your house lost the neutral, your supposed "120V" goes well above 200V! It depends on the load on each half of the secondary, and if parallel paths are present; also how "good" of a path they are.

Sorry dude I moved from there 2 years ago. The distribution transformer blew up (literally like a cannon going off) 5 or 6 times because our power company is independent and have the 3 phase distribution to the homes over loaded. The transformer would literally glow at night in the summer months. (now they finally put another one further up in the easement so it no longer blows up or glows) I bought my home and I am just around the corner from there now but my power is good now it is off a street run.
The TV's power supply is bad it needs a mosfet and probably a diode or two. It was turning on but would then cut back off, and in a past diagnosis I found out that it is the power supply. I didn't want to spend the money for a board but now I have learned a bit more and thought i would give it a try actually repairing the board myself. Until I saw the mystery water.

I had no Idea the thing had coolant in it... LOL

[kaboom]

Re: Water inside Panasonic projection tv mystery

Sorry dude I moved from there 2 years ago. The distribution transformer blew up (literally like a cannon going off) 5 or 6 times because our power company is independent and have the 3 phase distribution to the homes over loaded. The transformer would literally glow at night in the summer months. (now they finally put another one further up in the easement so it no longer blows up or glows) I bought my home and I am just around the corner from there now but my power is good now it is off a street run.
The TV's power supply is bad it needs a mosfet and probably a diode or two. It was turning on but would then cut back off, and in a past diagnosis I found out that it is the power supply. I didn't want to spend the money for a board but now I have learned a bit more and thought i would give it a try actually repairing the board myself. Until I saw the mystery water.

I had no Idea the thing had coolant in it... LOL

Remove the flyback, wash the board, and try again. Bet it stays on with audio.

I think you're referring to the open-wire secondary that was overloaded. Old neighborhoods used to have but one transformer, about in the middle, with the 120/240 feed "wingspreading" in both directions. The biggest load anyone had when such developments were built was a washing machine. Maybe an electric dryer, but where power was "scarce," gas dryers ruled (also cheaper per BTU).

You probably saw the jumper from the transformer's secondary to the bus glowing, from 4:27 onwards:

(secondary bus got together)
https://www.youtube.com/watch?v=4nLcjDmGr6g

Anything the center tap conductor returns to the TX at this point is of such high current, the "far end" of that supposed neutral rises, resulting in almost the same imbalance as with an open neutral: 120-0-120V ends up as 60-60-120, as measured to a remote "true" ground, like the CATV shield.

[stj]

Re: Water inside Panasonic projection tv mystery

can you post a foto of the front of the tube and lense.
there is usually something sticking out of it like a small bottle to handle expansion when it all heats up.

btw, the coolant is to stop the phosphorous on the tube burning because the brightness is so high.

[Doc38343]

Re: Water inside Panasonic projection tv mystery

Remove the flyback, wash the board, and try again. Bet it stays on with audio.

I think you're referring to the open-wire secondary that was overloaded. Old neighborhoods used to have but one transformer, about in the middle, with the 120/240 feed "wingspreading" in both directions. The biggest load anyone had when such developments were built was a washing machine. Maybe an electric dryer, but where power was "scarce," gas dryers ruled (also cheaper per BTU).

You probably saw the jumper from the transformer's secondary to the bus glowing, from 4:27 onwards:

(secondary bus got together)
https://www.youtube.com/watch?v=4nLcjDmGr6g

Anything the center tap conductor returns to the TX at this point is of such high current, the "far end" of that supposed neutral rises, resulting in almost the same imbalance as with an open neutral: 120-0-120V ends up as 60-60-120, as measured to a remote "true" ground, like the CATV shield.

Ours was like this only the final pop was louder.
https://www.youtube.com/watch?v=rHVh0KwG_0k
It did look the same those insulators. And you are absolutly correct open three wire, the first squirrel killer extraordinaire! Had to be 3 to 5 fried every week and it is still that way today!
On my street they can just use the bucket trucks so we get the new fancy tri-plex.

[Doc38343]

Re: Water inside Panasonic projection tv mystery

can you post a foto of the front of the tube and lense.
there is usually something sticking out of it like a small bottle to handle expansion when it all heats up.

btw, the coolant is to stop the phosphorous on the tube burning because the brightness is so high.

I will try I have to get some actual work done but ASAP
It's been sitting there 2.5 years... no hurries, I just hope I can learn a bit.
Never worked on one of these before.
Seems like a lot of trouble. I will try and get some good photos now that I know better where to look.
Thanks

[kaboom]

Re: Water inside Panasonic projection tv mystery

Ours was like this only the final pop was louder.
https://www.youtube.com/watch?v=rHVh0KwG_0k

That's not a transformer fire. It's either a failing arrestor or broken Chance cutout. It's the fuses that go "bang." They're loaded with a charge that knocks them out, to avoid drawing an arc.

This is a transformer fire:
https://www.youtube.com/watch?v=7DzVsUdbGwA