Projection TV is out of focus

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

Solution #1 posted on Feb 28, 2009
Ecollier2012Rank: Guru
Rating: 91%, 106 votes
Your TV most likely has one of two possible problems.

Problem #1: Convergence Chip 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.
Projection TV is out of focus - 77ea520.jpgrc="/uploads/images/701cb04.jpg" altProjection TV is out of focus - f0900cb.jpgpg" class="h_mi" />


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 righProjection TV is out of focus - 2c07611.png />If you can't move them in all directions your convergence chips are bad and should be replaced. This is a common problem.

Solution #1

You need to replace the convergence chips and convergence resistors. Check the site www.TvRepairKits.com. They have put together a kits for most models. If you don't see a kit for your set send them a quick note and they will put one together for you. Their kits include a photo instruction guide, original OEM Sanyo STK chips, convergence resistors, pico fuses, etc.


Problem #2 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 haloProjection TV is out of focus - 578ba6c.jpgages.

Picture of a set that needs the fluid changed.
TV set after fluid change



Solution #2


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.

Hello hocusfocus,

I posted this before, but it fits your problem too, so here goes:

You have a convergence amplifier problem. This is a common problem in these types of televisions. The fix for this problem is to replace the two convergence amplifiers in your tv. These amplifiers usually go bad along with the associated bias resistors. I would suggest that if you are going to do this yourself you should use only the manufacture recommended replacement parts. There are many who will tell you to upgrade the amplifiers, but my experiences have told me this is more trouble then it is worth, if you don't plan on redesigning the circuit itself. So with that being said, here is the basic procedure:

1) Get a schematic for your set (to be used in parts location and alignment instruction)

2) Using the Schematic locate the STK329-xxx or STK392-xxx series amplifiers (They are the two large six sided components attached to a large heat sink on the deflection board)

3) unplug the TV set

4) remove the deflection board from the TV set

5) using a soldering gun or iron with either a de-soldering pump or de-soldering braid remove the solder from the pins of the amplifiers and the associative biasing resistors.

6) remove the amplifiers from the heat sink and clean the heat sink off with alcohol or a solvent designed for removing the silicon paste.

7) coat the metal plate of the new amplifiers with heat sink paste and install them on to the heat sink.

8) install the associative biasing resistors

9) solder all of the components, making sure not to create solder bridges (short circuits) on the printed circuit board.

10) inspect the soldering job for bridges and cold solder joints (touching the joins up if they are cold)

11) reinstall the board to the television (reconnecting all cables removed.

12) power up the TV and perform the alignment instructions in the schematic

13) set the alignment of the TV

14) perform the magic focus setup

This should complete this task.

Now if you feel that you can not do these tasks, please consult a qualified TV technician about doing this for you.

I hope this helps

Thank you,

Shuttle83

http://www.electron-age-technologies-llc.com