The picture tube on my T.V. has been getting 'waves' of color flashing across it periodically for the last few months. Over the last couple of days we have noticed that there seems to be a large cross pattern of bad color for the bulk of the T.V. screen, and the color only seems good for about 3" rectangular sections on all of the corners. This phenomenon is perfectly symetrical.
Any ideas would be greatly appreciated!
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Re: Color in picture only good in 4 corners
I think it is a magenatic effect called degaussing problem.
please remove anything very near to it which has got magnet like speaker headphone etc.
call tech to gegauss it. it is hardly 5 minutes job.
please do not change the angle while watching tv.
your tv seems to be 100% ok.
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This could be a heater-cathode (H-K) short in the CRT, a failure of a
component in the chroma circuits or video output (driver board), or bad
connections there or elsewhere.
Don't panic - heater-cathode shorts in CRTs can often be worked around.
Note: before proceeding, it is a good idea to make sure that the screen is
degaussed - else you could be attempting to track down problems with the wrong
Some simple tests can confirm or rule out other possibilities.
Compare the voltages for the video drive signals to the CRT on the little
board on the neck of the CRT with the CRT both connected and unplugged.
A schematic will help greatly in locating these signals.
If there is a significant difference especially on the bad color, then the
CRT is a likely candidate. Try tapping the neck of the CRT GENTLY (with
it plugged in and while viewing a picture) to see if it is an intermittent
If there is no significant difference, you may have a bad driver or a
problem in the chroma circuits.
Look for bad connection/cold solder joints, probably on the little
board on the neck of the CRT. Use an insulated stick to gently prod
the board and its components in an effort to induce/cure the problem.
Look carefully for hairline cracks around the component leads.
You can swap components between two colors and/or test with an ohmmeter
on that driver board to determine what is bad. The nice thing about
color monitors and TVs is that there three copies of each of these
components. Swapping and/or comparisons between these is an excellent
Another simple test: Disconnect the cathode for the full-on color from its
drive. If it is still full-on, there is probably an H-K short in the CRT
since the only way to get each color on the screen is via the cathode
connection to the CRT neck board. If it is removed and there is still that
color, the current must be taking another path inside the CRT.
Alternatively, interchange the outputs of the bad color with a good one
by jumpering on the video driver board (on the CRT neck). If the bad
color changes, then the problem is in the circuitry and not the CRT.
So you have to get a tech if the above method doesn't solve your problem and get it fixed..
Goodluck, Please don't forget tor ate me as fixya..
Convergence is dead.Know how to solders?Must replaced the 2 convergence ICS,and all it resistors to solved this problems.Buy a convergence kit to fix it ur self.Tries Tv repair World.com,Tvrepairkits.com for the convergence kit.The shop will cost U $300 for parts and labors.
for the color problem,most likely you do have problem with loose contact of components from C-board ( small board connected at the back of CRT "picture tube" which drives every color and size of the screen)if you have knowledge with soldering electronic component parts, resolder this board and also check main board for possible loose contact.
Unfortunately, this sounds familiar. Many of these sony projections had bad crt's.(picture tubes). Now here is a secret I learned along the way. The short in the picture tubes is in the filament, causing that color to overpower all others and sometimes causing pix to disappear until set is shut off and back on. If you are very careful and use an insulated screwdriver, you can sometimes tap on neck of picture tube and knock debris from filament causing extended tube life. This is dangerous and must be performed with set turned on. From front of set gently tap on neck of tube(s) in question using insulated handle of screwdriver to make contact with picture tube neck. Picture will probably flash whichever color tube is contacted. Eventually, if picture stops flashing that color as much, you can sometimes get several more months out of your set without any problems. Only alternative is to try a crt rejuvinator or replace tubes at a cost of 200.00 each if avail. plus labor. Good luck, Russmann.
use the advanced options page and reset the factor blue and red convergence defaults then do re apply the auto color defaults color at first it seemed very red (which is good because red was the missing factor in the green picture) but after reseting all the color and tints to the normal ranges I then reset the color auto correct again and all seems fine.
I am in agreement with the second solution. TVs, when moved from one location to another have a tendency to show color patches in the corners. A few days of usage, and the auto degaussing circuits will clear the problem. Also make sure that there are no Magnet Sources nearby (Un sheilded Speakers, some Power supply of amplifiers, A 2-in-1 music system, your kids walky-talky toy, etc.)