Procedure for changing CRT Coolant

[NTL1991]

I have a 64" Philips/Magnavox RPTV and I've noticed some algae and crystallized spots in the CRT lenses and I want to empty out the coolant in the Red, Green, and Blue CRTs, Clean it, and then refill with new coolant. Some say it's better to empty and refill the coolant in the projection cavity behind the screen, and some say its better to go in the "guts" of the TV and Remove the 3 CRT's then empty and clean them then put them back in, but then they are faced with the realignment process which has me afraid. Does anyone have a step-by-step procedure to change the Coolant in a Magnavox RPTV?

Thanks a Lot,

Nick

[hammerdwn]

http://www.avsforum.com/avs-vb/showthread.php?t=665976

Hammer

[Ballz2TheWallz]

I've never heard of this issue

[NTL1991]

Thank You SO Much, You don't know how much I appreciate it. Im going to buy the coolant later this morning...

Thanks Again,

Nick

[NTL1991]

Originally Posted by Ballz2TheWallz

I've never heard of this issue

Do you have a RPTV? If you do, then you should. I wasn't aware of it until I got the "green haze" problem...

Nick

[Ballz2TheWallz]

Originally Posted by NTL1991

Do you have a RPTV? If you do, then you should. I wasn't aware of it until I got the "green haze" problem...

Nick

how fast does this kind of thing occur

You'd think they would put coolant in them that isn't a live-able enviorment for algae(i have a hitachi, seems like this is a problem for magnavox?)

[NTL1991]

I've heard that Most Magnavox RPTV's need a coolant change. My TV is 7 years old but some are newer (even 2001's) and some are like 12 years old... I guess it was a flaw in Magnavox's manufacturing? Some say RCA's rarely need it... But if you have halos or shadows or a noticebly red picture then it probably the coolant. You should check your blue gun... I'd bet you'd find some crystalized spots in it. This is what my Blue Gun looked like...

Nick

[Ballz2TheWallz]

Originally Posted by NTL1991

I've heard that Most Magnavox RPTV's need a coolant change. My TV is 7 years old but some are newer (even 2001's) and some are like 12 years old... I guess it was a flaw in Magnavox's manufacturing? Some say RCA's rarely need it... But if you have halos or shadows or a noticebly red picture then it probably the coolant. You should check your blue gun... I'd bet you'd find some crystalized spots in it. This is what my Blue Gun looked like...

Nick

What about hitachis I'm hopeing i won't need to shell out $300 to fix it in the near future(5years)

I plan on buying SED when its out of its infancy though....so i won't be keeping my set forever(might throw it into the livingroom when i get SED)

[NTL1991]

I dont know about Hitachis but it probably depends on how old it is. And alot of people have done coolant changes, and I think that you are capible of doing it too, like most of us. You just need to know what all the different parts are, and most importantly, do some research before hand.

As for me, I don't think I could cope with getting a smaller TV. I have a bigger TV than most people now, and I hope It will last me a good 4 more years until they can come out with a LCD or Plasma 64" TV... Or maybe a DLP RPTV? I dont know yet. Those SEDs dont sound that bad though.

Nick

[Ballz2TheWallz]

Originally Posted by NTL1991

I dont know about Hitachis but it probably depends on how old it is. And alot of people have done coolant changes, and I think that you are capible of doing it too, like most of us. You just need to know what all the different parts are, and most importantly, do some research before hand.

As for me, I don't think I could cope with getting a smaller TV. I have a bigger TV than most people now, and I hope It will last me a good 4 more years until they can come out with a LCD or Plasma 64" TV... Or maybe a DLP RPTV? I dont know yet. Those SEDs dont sound that bad though.

Nick

Mines brand new still worries me though

[JohnnyG]

Originally Posted by NTL1991

Thank You SO Much, You don't know how much I appreciate it. Im going to buy the coolant later this morning...

Careful now! That article leaves much to be desired. First, both the red and blue CRTs are mounted on an angle so as soon as you remove the top cover, the fluid will come gushing out. The stuff is electrically conductive and a nightmare to remove from circuit boards, so you do not want to lose ANY of it.

I would strongly suggest removing the CRTs and using the drain/fill plug for the coolant.

[hammerdwn]

Ya in fact I say you should NEVER attempt a coolant change with the crt still mounted in the Tv!!! You should take the crt out first, or you will be sorry.

Hammer

[mbaxter]

Originally Posted by NTL1991

As for me, I don't think I could cope with getting a smaller TV. I have a bigger TV than most people now, and I hope It will last me a good 4 more years until they can come out with a LCD or Plasma 64" TV... Or maybe a DLP RPTV? I dont know yet. Those SEDs dont sound that bad though.

Um, you do realize they've had DLP RPTV's on the market for years...

[NTL1991]

Yes, but I mean come down in price... Do they have DLP's over like 60"?

Nick

EDIT: OK, Now I see some over that... Im surprised how cheap though, a 72" Toshiba DLP Rear-Projection only runs about $5200. That's not that bad.

Nick

[NTL1991]

Originally Posted by hammerdwn

Ya in fact I say you should NEVER attempt a coolant change with the crt still mounted in the Tv!!! You should take the crt out first, or you will be sorry.

Hammer

Yeah, I've heard of too many people who spilt coolant all over thier boards and then they were sorry... But what about this daunting "Realignment" after you remove it? Is it that hard? I have heard alot say that it takes hours just to realign the crts... Or is this just convergence?

Thanks

Nick

[hammerdwn]

Quick guide to removal/install of crt:
Tighten the lens adj nut.
Remove crt board, svm board/windings, yoke/windings, ground wires (suggest labelling/marking posistions so you don't end up with an upside-down picture), and HV anode from Flyback/Tripler.
Unscrew from mount, lift out.
Detach lense assembly from tube.
Split, Clean, Refill, Seal.
Now put crt back in, assemble in reverse, apply power and hope for the best.
You will have to do mech convergence, digital convergence, hardware grayscale, and maybe SM grayscale.
If you are doing more than one, do them one at a time (get mech convergence close on the new crt before removing the next one).

Hammer

[NTL1991]

Originally Posted by hammerdwn

Quick guide to removal/install of crt:
Remove crt board, svm board/windings, yoke/windings, ground wires (suggest labelling/marking posistions so you don't end up with an upside-down picture), and HV anode from Flyback/Tripler.
Hammer

Now are these boards/cables marked?

Nick

[hammerdwn]

Ya right

[John Mason]

Acquired the service CDROM when I bought my year-2000 64" 9"-CRT Philips RPTV (64PH9905), and it outlines the coolant change procedure and part numbers. Got my CDROM (manuals also available) through Philips' parts department after C.S. transferred my call. Some Googling might reveal firms that market service manuals, too. A major undertaking for anyone inexperienced. Likely best to pay a Magnavox/factory specialist, and even, considering the cost, writing the display off and getting a new one. -- John

[NTL1991]

Well, Im perfectly capible of doing it, I just need to do a little more research and remember all those tips I got from other forums... As for getting a new TV... Were thinking about getting a new TV in the next 1-2 years when we buy a new house. We will then put my Harmon/Kardon system down there too. My Bedroom is too small for that kind of sound.

Nick

[NTL1991]

OK... The coolant is on its way. I bought 3 cans of the 16oz just in case. Now I need to buy a turkey baster because mine is somehow ripped .

Thanks for the guidance

Nick

[John Mason]

Appreciate the update and would be interested learning what you saw on screen before/after. Haven't reviewed the procedure on my CDROM, but assume each tube must be removed, the fluid removed and the cavity really cleaned to eliminate all the biological growth, then the whole system mechanically realligned and converged again after refilling. A turkey baster...nice. -- JOhn

[NTL1991]

"What you saw on the screen before"... Would that be the green haze around everything white, and the picture being really red?

Yes, You got the Procedure Right.

Yeah, most people say that a turkey baster works great for removing the coolant.

Nick

[NTL1991]

And, hammerdwn... Mechanical Convergence, Is that by using those greed, red, and blue dials I saw near the CRTs?

Nick

[hammerdwn]

Those dials are G2 screen controls and focus controls for each crt. Mech convergence is first getting the yoke back on straight, then below the yoke is a ring with some magnetic "wafers" they look like flat rings with tabs sticking out. If you mark the position pre then post will be close.

Hammer

[John Mason]

If you adjust the screen control (next to focus pot) on the card-deck-size focus board (usually has six RGB potentiometers), you'll mess up the grayscale balance, which will require a tech/calibrator equipped with the right optical instrument. Suggest being careful making adjustments. As menitoned earlier, the model's CDROM or paper manual spells out what to do and how to adjust all controls. -- John

[NTL1991]

I've gone and emailed different service manual companies and they said they don't have the one for my model. UPS says the coolant should be in tomorrow and I was surprised by how heavy it is. Is says 6 pounds; I got 3 cans of 16oz. Is it just packaging?

And, I have a picture I took. Those 6 dials are the one's I'm talking about. Is there anything you can tell my by looking at that setup, beside it needing a VERY GOOD dusting?

http://nicklester.com/files/nick/images/TV.jpg

Thanks,
Nick

[John Mason]

The 6-pot board looks a bit similar to that in my year-2000 Philips 64" CRT RPTV. I cleaned the mirror and lenses a few months ago, tweaked the RGB focus pots (no major change), carefully avoiding the SCREEN pots, and tried refocusing the 3 lenses (also no great change). Was trying to see 480i or 1080i scan lines again, which haven't been visible for several years, although HDNet's 1080i resolution wedges--and other SD/HD programs--still seem crisp, with 1335-lines once resolved (RCN Cable) and maybe up to ~1600 lines resolvable, although my current cable firm/STB puts a 1290 limit on resolution. -- John

[NTL1991]

Hellol. I am going to leave the CRTs in the Unit, but I cannot find the expansion ports. What are they? Where are they? Can anyone point them out in the picture I have linked above?

Thanks,

Nick

[hammerdwn]

Looks like maybe these...