Magnovox Projection Problem

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Ito
Magnovox Projection Problem

I have a 46 in magnovox rear projection tv and works great except for there is a yellowish green spot in the center of the screen. Anyone ever had this problem and any ideas of how to correct this? Thanks

Larry Dillon
Does the Picture look like

Does the Picture look like its in three-d(3-D)?  Can you send me a picture?  What type of set, LCDprojection, Plasma projection, tube type projection.  model number and chassis please if possible.

Ito
Model number:FP4630 W105

Model number:FP4630 W105 Chassis Model Number:PTV620-AH01  The picture looks fine just a green blemish directly in the center of the screen.  Its just a reg projection (3 lights inside). I removed the screen and cleaned the lens, removed the top lens and there is dirt in the fluid, could that be the cause?

Larry Dillon
Yes thats what the problem is

Yes thats what the problem is. Check this out
Changing Projection TV Coolant

1. Tip the TV set so the expansion chambers are pointed up. The expansion chamber is a small white/clear

plastic bulb-like thing That is attached to one side of each of the CRT's up near the top lens. In some TVs,

the expansion chambers are already pointed up - In this case you don't have to tip the TV

2. Cover the circuit boards below the CRT's with several paper towels to prevent accidentally spilling any

coolant onto the boards. The coolant is corrosive and will destroy the circuit boards. Don't skimp on the

paper towels here - they are cheap!!!

3. Remove the four screws that hold on the focusing lens assembly and remove the focusing lens assembly.

4. Note the position of the expansion chamber then remove the expansion chamber. It will need to be

reinstalled in basically the

same position so remember the position or take a picture if you need to. There is a small o-ring on the neck

of the expansion

chamber where it threads onto the CRT housing - Don't loose it!

5. Use the baster and tube to suck the fluid out from the hole where the expansion chamber was removed.

This hole is fairly small...maybe 5/16" or so.

6. Once most of the fluid is out, remove the four screws that hold on the lens cover plate.

7. Remove the lens cover plate, the lens & the large o-ring. (be gentle with the o-rings!!!)

8. Clean the CRT chamber & lens with denatured alcohol. Use 100% cotton balls so you don't scratch anything.

9. Clean the CRT chamber and lens with distilled water. Again, use 100% cotton balls so you don't scratch

anything. This will rinse

out the alcohol residue. You need to use distilled water for this so there is no mineral residue.

10. Gently clean the large o-ring with distilled water (don't use the alcohol because it might eat the o-ring)

Dry off the o-ring and lightly coat it with 100% pure silicone (not siliconized acrylic caulking or acrylic

latex caulking - ONLY USE 100% SILICONE).

Use your fingers to rub a thin layer of silicone all over the surface of the o-ring. Then place the o-ring in the groove in the CRT housing.

11. Place the lens in its position on the o-ring.

12. Place the lens cover plate over the lens and install the four screws.

13. Clean your baster and tubing with denatured alcohol then rinse with distilled water.

14. Use the baster and tube to suck clean fluid from the bottle and install it into the CRT through the

expansion chamber hole. Go really slow when it is almost full to minimize overflow. Wipe up any overflow

immediately. There will be a small air pocket in the CRT when you are done - you will not be able to fill

the chamber 100% - This is O.K. Just be sure to fill it as far as possible so the fluid is just up to the edge of

the expansion chamber hole.

15. Install the expansion chamber. Be sure to install it in the same position as it was before you removed it.

Also be sure that the small o-ring is on the neck of the chamber before you thread it on. The chamber is just

plastic so don't over-tighten it or you might damage it. Screw it on as tight as you can go by hand and then

give it about 1/8 of a turn with pliers. (you might have to use needle-nose pliers to get a good grip on it.)

16. Place the focusing lens assembly into position and install the four screws.

17. Turn on the TV and check for leaks over the next 20 minutes. Remember, you have not yet removed all

the paper towels from inside the TV. Remove these once you know there are no leaks.

Other things that should be done after replacing the fluid include...

1. Clean the mirror
2. Clean the top lenses of the focusing assemblies
3. Focus the CRT's
4. Adjust the convergence

Here is a list of things you will need:

1. Turkey baster
2. Vinyl tube
3. Cooling Fluid
4. 100% cotton balls
5. Paper towels
6. Denatured alcohol
7. Distilled water
8. Pliers
9. Screw driver

Ordering Coolant:

http://www.mcminone.com Part # 20-2041

My TV used just a bit more than one bottle to change all three so I would suggest ordering two bottles.

alwaysalready
You might have phospher burn

You might have phospher burn caused by a problem in the past like deflection failure. Cover two picture tubes and see if you still have the spot then cover the first one and uncover another by the process of illimination you will find out if all the tubes are burned or just one. Usually when you have contaminated coolant you lose contrast and brightness in the blue and green tubes and the red is clear and fine.If you look inside the tubes with a flashlight you can see a fungus like growth growing inside dimming the light output of the crt. I never saw contamination just affect the center of the tube.

Ito
The part# you gave me for the

The part# you gave me for the crt coolant is no longer available, there is one in a 16oz. bottle would 2 of those be enough to fill all three?

Larry Dillon
Yes Two should be enough for

Yes Two should be enough for the three CRT Its been a time since I changed the fluid. Oh your right they changed the part number on the coolent, its new number is 20-4275. Also befor you order and change the fluid, look in to all three CRTs and make sure you do not see any burn mark or spot on the surface of the CRT screen. if there is and it does not look like a contaminate, you will have the same problem when you change the fluid. So please make sure first. Oh By the way, if you want this job to go well and dont want to tip the set, use the pump they have to do this job. Lets us know how you make out please.

Ito
Any ideas where i could

Any ideas where i could purchase some denatured alcohol i tried serveal places and no luck? I have the fluid and am ready to try this thats the last thing i need to get. thanks

Ito
Found the alcohol and changed

Found the alcohol and changed the fluid, everything went smoothly. The spots are gone and it is brighter but now the picture is blurry, is that because of something i did wrong?  Picture wasn't blurry before i changed the fluid. Any idea's

Larry Dillon
There is a focus block that

There is a focus block that has the three (RGB controls on it along with the three differant screeb controls. Look closely at the three focus cobtrols. Look at each one and while adjusting the said color, look intop the samne color picture tube and "rock" the focus cobtrol Back and forth while looking inside the front of the lens to tweek the focus for each color.

Ito
Thank You so much the picture

Thank You so much the picture looks great.

Larry Dillon
Great!  Im so glad you did

Great!  Im so glad you did not give up and followed all the instructions to the letter.  Keep us in mind and tell all your friends about us.

StephThomas
Larry - can you please read

Larry - can you please read my post about the 42" black screen problem and email me? you sound the the man i might be able to get some good info from

Ito
Hi Larry, Its been about a

Hi Larry, Its been about a week and that spot is slowly starting to come back, Does this mean that something else is wrong?

Larry Dillon
Look into the lens while the

Look into the lens while the set is on.  Whats floating around inside?  What color?

Ito
there was a little cotton

there was a little cotton from a cotton ball that was left in there from when i cleaned the lens out, i drained the fluid and cleaned it out and it seems fine now, thanks again

Ito
to focus the picture each

to focus the picture each lens has to be adjusted seprately on this set and it is very difficult to get it right,  is there a trick to this?

Larry Dillon
I always use the cross hatch,

I always use the cross hatch, and cover two colors, adjust the one then cover the color you just adusted. One color at a time is the rule.

brol
I have a 42" sony rear

I have a 42" sony rear projection LCD tv. After about 1.5 yrs I developed multiple ( >10) red to blue spots near the center of the screen. Each spot is about 1 cm. They show up mainly on lighter backgroud screens. Also, I just started getting a bluish discoloration at the bottom right corner. With a blank screen ( dark blue) the discoloration is a lighter blue and about 4 square cm. What could this be? Thanks

Larry Dillon
Your in the magnavox section

Your in the magnavox section and asking about a Sony TV set.  That really would not be a problem BUT whats the model number??  The light engine is most likly bad on this set.  Did you purchace an extended warranty on this set?

 

 

brol
Sorry about posting in the

Sorry about posting in the wrong section. My bad. The model number is KDF-42WE655. I do not have the extended warranty. The set is a little more than 2 yrs old. Thanks

Larry Dillon
This sure as heck sound like

This sure as heck sound like microdisplay LCD panels in your light engine could be getting tired and going bad.  In some instances the outer main lens could need cleaning but unlikly.  Also Have you ever changed the bulb in this set?  Thats also a possibility but only a pro would be able to tell you this.  This is not a job for the do-it yourselfer.  This is a very expemsive part.  Check with sony and see if this is one of the models that have a problem with these microdisplays.  Good Luck, and let us know how you made out with this set.

brol
Larry Dillon said: This sure

Larry Dillon said: This sure as heck sound like microdisplay LCD panels in your light engine could be getting tired and going bad.  In some instances the outer main lens could need cleaning but unlikly.  Also Have you ever changed the bulb in this set?  Thats also a possibility but only a pro would be able to tell you this.  This is not a job for the do-it yourselfer.  This is a very expemsive part.  Check with sony and see if this is one of the models that have a problem with these microdisplays.  Good Luck, and let us know how you made out with this set.

Thanks Larry. I have never changed a bulb. Is it difficult to change the bulb?

 

endure2n
Hey larry can I fire a

Hey larry can I fire a Question at you????

endure2n
Got a hitachi 51G500A rear

Got a hitachi 51G500A rear projection TV .....Its got the three beams in it. My red is off....I tried magic focus no good......tried manual and still no good....any ideas.

Larry Dillon
Brol, it might not be the

Brol, it might not be the bulb. It should be in the instruction or user manual how to do this and how to tell if the bulb is bad.

Larry Dillon
Endure2n, are you trying to

Endure2n, are you trying to say the convergence is off.  Please be a little more specific if you can.. The red beam is off?  I dont know what a beam is, sorry.  If you tries to adjust the magic focus i quess you are talking about the convergence not adjusting.  It sounds like a typical convergence falure that happens in every or almost every, it seems, CRT type projection set ever made.  There are Two STK type convergence IC's that have to be replaced.  First thing to ask, do you have a service manual, and do you know how to use one, and read a schematic diagram?  Second, do you know how to solder and unsolder on solid state  printed circuit boards?  Do you know and own a multimeter?.  If the answer is no to ONE of these questions , My freind, play it safe and call out a pro to assit you in this repair.  This TV is no place to be experimenting inside of.  Good Luck, and let us know how you made out.

Mamma
I think I have a problem

I think I have a problem similar to Ito. I have a 46" Magnavox Projection Screen TV Model # FP4625 W103. It is a crt projection screen. It has three splotches in the center of the screen that look red when there is a white background. I discovered it is not the red beam. After covering each light, I found that the green one is the culprit. When I look down in the green lens, I can see splotches of dirt and dust. Actually, all lenses look like there is dust under them. Can you tell me the correct procedure for removing the lenses to see what is underneath them. Is it possible there is just a lot of dust buildup under them rather than needing new coolant?

Larry Dillon
Mamma-Mia, nope I am sorry to

Mamma-Mia, nope I am sorry to say that dust cannot get in there as thats why the fluid is there.  To cool off those hot screens of the picture tubes and to keep dirt and dust from building onto the surface of the picture tubes.  Follow the directions under the previuos post I left for Ito and you should be fine.  A very inportant thing is NOT to get any fluid on the printed circuit boards and please make sure the set is unplugged.  If you do not feel comfortable doing this, as after all there is alot of high voltage inside this tV set even after it is unplugged, play it safe and call in a pro or someone you think can do this.  Bottom line Mamma, play it safe.  Good Luck, and let us know how this repair turns out.

John_Jenkins
No Power in Magnavox PTV620

No Power in Magnavox PTV620-AH01, FP4630 W104. Does this unit have a power supply that can be replaced? What would you think the problem is? No power indicator light either.

Typezer0
CRT coolant change and

CRT coolant change and advanced convergence - how to

I documented the procedure I did on a Philips 55" rear projection 55p916

http://tinyurl.com/lmp6eu
CRT coolant change procedure

http://tinyurl.com/l7bd7r
basic and advanced convergence

 

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