Coolant leak and possibly short fuse problem on CRT RPTV

If the pic on your CRT RPTV is bleary, its front viewscreen is not the problem, and no, your set is not worn out even tho it really looks that way.
The solution is that the internal optics need to be cleaned, due to the high voltage inherent in CRT use. Remember how your old, thick computer monitor would get incredibly dusty on its face? That's because of the HV ionizing all nearby particulates and charging them with static cling. They then drift to and deposit themselves directly upon the closest smooth surface - in the case of CRT computer monitors, the face of the monitor. In the case of CRT RPTVs, the mirror and lenses. In other words, at certain very critical points on your 28 surface optical chain that comprises the CRT RPTV's projection light path.
Optics cleaning should happen once a year without fail, otherwise you're really not getting your money's worth out of your multi-thousand dollar set. And CRT HD ready RPTVs are classics, with 20 year service lives.
On some units only 4 surfaces need to be cleaned, like Mit. On others, like Pioneer, 10 of the 28 surfaces need to be cleaned.
But be very careful, these lens surfaces are made of very soft, vulnerable plastic, and are very easily scratched or - even worse - scuffed, which is thousands to tiny scratches at once. The mirrors in HDready sets are front surface or mylar - you are not cleaning glass at any point, with these sets.
As such you need to be painfully careful, as damage is immediate and permanent. I recommend contacting me directly before doing any optics cleaning on any projection set, esp. CRT RPTVs.
But oh, what a difference a day makes! This can all be done in a day, after which your CRT RPTV will look like a new TV again!
Mr [email protected]
As such them

pidksmith,

If you see something leaking from the blue tube it is probably coolant. You will need to find the leak and repair it and fill it with the proper amount and type of coolant. Projection TVs with CRTs have to have coolant covering the face of the CRT or they will overheat. Sometimes they can develope a leak. You will need to unplug the unit and remove the rear lower cover. Looking at the blue CRT from the top you should see 4 screws holding the lense on to the crt. Do not remove any other screws or you will change the mechanical focus. Remove the lense and look for the leak. If it can be fixed use good epoxy to seal it. Order a bottle of CRT coolant from http://www.mcmelectronics.com . There should be a filling port on the top of the crt. Fill the chamber to the required level, close, reassemble and you should be back in buisness. If the leak cannot be fixed you would have to replace the crt. I have a tip for that at http://www.fixya.com/support/r4573850-change_crt_in_projection_tv which explains how to do this.

Thanks for using FixYa and for the great rating.

hardrocko

This is a very common failure on Projection TV sets.

• 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 settings menu then goto the convergence section.

Try to adjust the red and then the blue convergence.

You should be able to move RED and BLUE in all directions - 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.

Note: If you TV has as flash focus or magic focus button only try pressing the button. If it fails to fix the convergence your need to fix it. See below for a solution

SOLUTION

You will need to replace the convergence chips and possibly some convergence resistors and pico fuses.

This is a a fairly easy DIY job if you know what you are doing 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 step by step instruction guide, original OEM Sanyo STK chips, convergence resistors, pico fuses, thermal paste, email/phone support, etc.

Problem #2 CRT Fluid is Cloudy

Projection 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 video.

Pic of a set that needs the fluid changed. Notice how dull the colors are and how white the screen looks. The screen may also look red, orange, dull, etc.



TV set after fluid change. Notice how bright the colors are now. Everthing looks crisp and sharp again.





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,step by step instructions, etc.

My friend it seems like it's about time for this set to retire there is a high voltage in a low-voltage flyback or line output transformer even if the TV is off and unplugged they can kill you if you have a voltage leak and you really want to keep this TV I would take it to a professional television repair shop they will have all the tools necessary to diagnose properly so please be careful when inside a CRT television good luck in your effort to repair the set

Yes the puddle is related to the Blue CRT coolant leaking. You are most likely going to need a new Blue CRT drive circuit board and quite possibly a new Blue CRT if the CRT got too hot from not haveing a sufficent supply of coolant. You can get replacement CRT drives and CRts at the following link.
http://servicemanuals.vstore.ca/

There are a few malfunctions that can cause such.

ONE: Mirrors out of location. But it usually throws the picture off center, also. This can be caused if the set is dropped or kicked badly.

TWO: Out of focus. Can be caused by drift of the circuits or from a malfunction of the video drivers. You can check this by going to the crosshairs and see if the lines are sharp and narrow. If not, then the focus is off badly - most likely the blue gun. You may be able to set the focus and other levels for brightness and contrast and color to optimize this weakness as these are all somewhat interrelated, especially in the extreme settings. You can make adjustments for these above what is available from the OSD by getting into the service mode. See this web site for instructions on how to enter it. http://www.fixyourowntv.com/servicemenu.php

THREE: Worst case is the blue gun or projection tube is failing and needs replaced - which I don't recommend due to the very high cost of doing so.

FOUR: And it is possible the blue gun/tube has been knocked out of alignment by dropping or moving the set.

I favor the focus adjustment as the first remedy to try. You can do that yourself. But if it turns out the mirror is out of location or the blue gun is defective you will need a technician for help on those items.

If the lens came loose the CRT would leak its coolant all over the chassis. Sounds as if the Blue CRT may have a short and thats why its not working. If thats the case your looking at about 300.00 for a replacement tube if you install it about 600 if a shop does it.

The green Crt for your set is part number 251C207050. You said that you cleaned up where the fluid leaked but if even the slightest is left it can and will short this board. You are looking at about 200-250 for this CRT and if it leaked you would want it replaced. I couldnt find any in stock anywhere most had feb ship dates. You can get it from andrews electronics and union electronics.

Your TV most likely has one or more 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.

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 #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 halos around images.

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.

Do either the red or the green crts come up at all?? If not the heaters in the blue crt could be bad - loading down the HV and the shutdown circuit turns the set off.. Only repair for that is to replace the blue crt, but I would have it tested first.. In the shop here we use a B&K467 to test for shorts and emission leaks but that's old school.. B&K has since come out with far superior crt tester/rejuvenators..
Bill