Top 10 Philips Magnavox 51MP392H Rear Projection Television Questions & Answers

I bought a crappy old magnavox and rebuilt it. I had both of these issues.
Since your tv is old, the blur problem is probably caused by old coolant in one or more of the CRT lens couplers. Hopefully, the lenses are simply out of alignment, but no one has ever worked on the tv, then this is unlikely.


First, unscrew the back panel of the tv console (should be a bunch of 1/4" hex head screws). There will then be a large white panel at a 45 degree angle held in place by two tabs or maybe even screws. Remove it to see the CRTs. A quick check for the blurry problem is to look directly into the CRTs while the tv is off. DO NOT do it while they are on if you can help it, as it is not good for your eyes.
Shine a white LED flashlight down into each of the CRT's top lenses. Avoid classic incandescent light in this case, since you will be looking for the difference between white and yellow. I you see a white plate inside, good. If the inside looks yellow, and has floating things in it, then the coolant fluid inside is old and bad. You can replace this, but it is a VERY delicate task and MUST be done in certain steps to avoid ruining the electronic boards anywhere within splash zone or drip reach of the lens couplers. The coolant is a special blend available at most tv repair shops, but it's basically clear antifreeze (which you wont likely find in an automotive store).

For the color being off, it is most likely the gain on each CRT being out of whack. First, change all of the user settings (in the on screen menu) for image, color, sharpness, etc to the middle or default.
With the back panel off, somewhere near the bottom of the inside there will be a small black plastic box with wires coming out the sides. This box should have 6 knobs on the front of it (the face facing the rear of the tv); 2 rows of red, green, and blue knobs. These are the screen controls for FOCUS and GAIN. And they should already have some sort of label telling you so.
I placed a mirror in front of my tv so I could see the screen as I adjusted, but you might be able to see it somewhat by hanging a sheet over the front of the screen and looking at it from the inside.
There's a much more in depth method to do this that is described in the service manual (which you are likely to have seen by now; they are usually either stapled to the back of the tv or hanging somewhere inside and easy to see)
But basically, just turn the knobs gently around until the picture looks about right to you. (Remember, if you turn them all up super bright, the CRT will not last very long. Try to keep the knobs near the middle of their turn ability)


If you want to do a full out overhaul of the screen, you'll have to make a lot of adjustments with a bunch of little knobs (variable resistors, really) on the computer board inside. The service manual will tell you what each one corresponds to, but most of them will have a subtle label on the board.

Email me if you need any help

It sounds like the 3 "GUNS" are not aligned.
One the controls at the bottom, left hand side You will see an arrow pointing to the first 2 on the left.
That will allow you to scroll down the list of options until you see....CONVERGANCE!
make the red gun center by using the up/down arrows on right. Then add the next 2 until you see a white X or cross.
Thats it!
Mike

Yes,semiconductors is the term used to describe transistors,diodes,intergrated circuits(IC's)etc...the correct generic part# for that model is STK392-120 which is an intergrated circuit (IC)which in that TV works as a convergence amplifier.The specific Philips part# is 932212344682. There are two of them you need to change both. Also check the two 6.8 ohm resistors nearby if they are burnt or discolored.

I had the same problem where all of a sudden it started bowing on top and bottom and the colors were bad. I read on here and other sites about the 2 convergance chips so I figured why not try as the tv was going to get thrown away because I could not find anyone that would touch it. Well I ordered 2 stk392-120's (I know others are saying use the 150's or 180's but I just wanted to put the same ones that were in there) I ordered them from electronix.com for 9.99 each plus 6.60 for shipping they took 3 days to get here and I installed them tonight and it worked great. The whole thing took only about 2 hours from start to finish. Here's a couple of tips....the chips are on the far left when looking at the tv from the back, make sure you mark with a marker where the wires go that you have to unplug as there are about 10 of them, each chip has 19 pins that you will have to soder make sure you have a soder ****** to get all the old soder up as you are heating them up, after you are done puting it back together leave the back cover off and turn it on, then go into your menu and go to pictureand go to manual converge and go to undo multpoint and restore factory as this will reset it all. Then if your color is still a little off as mine was there are 6 knobs in the back of the tv by the chips you were working on, find a channel with a lot of colors and try adjusting the top 3 a little at a time till you get the right color that you like. This should do it. It took 26 bucks and 2 hours for me to fix a tv I was ready to replace, thank god for the internet to be able to look stuff like this up. Good luck!

Change the coolant inside the CRT this will restore the color and clarity to 100% on your set.

the screen on my hdtv has alot of marks on it how do i get another

You have one of two problems. Sometimes both.

Problem #1) CRT Fluid is Cloudy

Projection TV tubes have a liquid coolant that is used to keep them from overheating. After many years the coolant in the blue and green tubes will become cloudy and cause the screen to look dull, red/orange, etc. You may even see halos around images.

Picture of a set that needs the fluid changed.


TV set after fluid change




Solution #1


What you will need to do is replace the coolant and clean the crt. You can get a repair kit from www.TvRepairKits.com that includes replacement coolant, photos. instructions, etc.

Problem #2)

Your TV may have a convergence failure. ( common problem )

Here are some of the most common symptoms and example photos of a convergence problem

• Screen looks 3D
• Colors don't line up
• One or more colors can't be adjusted when using the convergence menu.
• Screen is bowed or warped.

Here are some photos of convergence problems.




Here is a quick test....

Using your original remote go-to the tv settings then goto the convergence section.

Try to adjust the red and then the blue convergence.

You should be able to move them up, down, left, and right.

If you can't move them in all directions your convergence chips are bad and should be replaced. This is a common problem.

Solution # 2

You will need to replace the convergence chips and possibly some convergence resistors and pico fuses. Its a fairly easy DIY job or you can call in a pro. If you want to do the repair yourself check the site www.TvRepairKits.com. Their kits include a photo instruction guide, original OEM Sanyo STK chips, convergence resistors, pico fuses, thermal paste, email/phone support, etc.

If you are using a comcast D.T.A. (Digital transport adapter) THAT LITTLE BOX FOR 2ND OR 3RD TV IN YOUR HOUSE. GO to channel with no sound then press LANG button on the remote that came with your DTA box. Press it only once. This worked for me .

Go to starchoice.com (or shaw) they have codes listed on their sites

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