THE SCREEN IS VERY DIM EVEN AFTER ADJUSTING THE BRIGHTNESS TO MAX.
ALSO AFTER ADJUSTING THE SCREEN VOLTAGE AND FOCUS ON THE FLYBACK TRANSFORMER,STILL NO CHANGES NOTICED TO THE
WHAT COULD BE THE PROBLEM?
Concerning the problem above i.e dim screen, my tube is ok, i replaced a capacitor of 22mfd 250volts but there was a slight improvement.
Im now planning to replace these capacitors around the power circuit.
I hope there will be improvements,please advice.
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There is a high voltage transformer(flyback) inside of this set that has two controls on it. One is for focus and the other is for screen control(brightness). You may want to try adjusting the screen control clockwise to see if that will help. The transformer is large, either black or gray, and has a thick red wire going from the top of the picture tube to it. It should be located close to the back of the set.I would try this first before I took it to the shop. Good luck!
This sounds like low screen voltage(A1)try adjusting the a1 voltage bottom control on flyback transformer if you have a voltmeter, voltage on crt base possible market screen or A1 shoud be beteen 350/500 volts when making adjustment remember to take into account current taken by meter If voaltage will not adjust flyback transformer will have to replaced
HIGH VOLTAGE WARNING - open the tv and on the flyback Xformer, there should be a knob that is labeled FOCUS try adjusting it. the flyback has the red wire on top that goes directly to the the top of the picture tube.
If those lines are slightly tilted (diagonal) you may be seeing the retrace of the horizontal sweep which isn't supposed to be visible.
At the loss of some brightness, adjusting the screen voltage on the flyback transformer (large, black block with a fat lead connecting to the forward side of the picture tube) may help but it is likely that there is a (possibly bipolar) electrolytic capacitor is failing.
This would be located near the flyback and is marked in some manner as bipolar and will be in the range of 10 - 30 uFd.
If you attempt this yourself, it will require a good deal of caution since there are potentially exposed high voltages in this area.
Some kind of insulated tool is recommended and the flyback will have two (rarely three) adjustment located on it; one will adjust focus, the other screen voltage.
If you are reluctant to try this yourself, it's OK, this kind of DIY isn't for everyone.
Is that diagonal thin line about 10 to 20 degree slant? And then you have a very bright raster?
Then you set the flyback(for tube tv), I think its "screen" voltage is set too high adjust it slowly to lessen the brightness. It is commonly a small pot on the side of the flyback together with the focus pot.
If you have raster turn the tv on, use insulated screw diver, then slowly turn the knob to the direction(CC or CCW) where your raster go dim.
Be careful your dealing with live and high voltage. If your not inclined on electronics better not to.
there is a problem in the flyback section of the tv set. the fly back has two knobs, one for screen and the other for focus. use the screen knob to adjust the brighness. if it did not help, either check the capacitors around the flyback or change the fly back with a new one. good luck
The picture is very dark
it is mostly due to
1 power supply output is low.
2 voltage on crt g2 pin is low.
3 video output supply is low.
4 some components in luminance section might be defective or loose.
5 finally crt getting weak is set is old.
If you feel good about opening your set then you can try this: Look for the flyback (high voltage) transformer, with the thick red wire which goes to the top of the picture tube. There are 2 controls on the flyback transformer, focus (top) and screen (bottom)Turn the brightness and contrast all the way down and then increase the screen control until you see retrace lines, and then back it down until those lines just vanish. Return the brightness and contrast to normal and adjust the focus control, if necessary, for a nice sharp picture. Let me know if that brings your brightness back.
Did you adjust the two controls on the new flyback? The top one is almost always the focus control and the bottom is the G2/screen control (brightness) If you adjust the G2 do it until the picture looks normal, too high and you will get retrace lines through the picture.