Have a problem with the colors comes and goes i had adjusted the voltages because I was getting a red screen and then it would power off was ok for about a month now it just seems to flicker of some sort and change colors Dont think its any of the convergence ICS but then againg not really sure Please help

Its possible one of two thing have occurred, you have maladjusted the G screen control on the high voltage screens and focus assembly. Turn down (counterclockwise) all three of the screen drivers. Adjust each until a light appears in the each lens, red green and blue. Go slow or lines will appear if set too high. If all three lamps stay lit after this adjustment the look at your screen with color level down to zero using your remote and the picture menu. Adjust the three color drives to get a good black and white balance appearing on the screen. Now adjust the color level from the picture menu back up to normal range.
If you still get green diagonal lines after this adjustment then I would suspect that the green lens has a heater to cathode short in the tube.

Check High voltage Block.After replacing ic's (STK convergence ic's) you need to adjust Black&White scale.Turn ALL screen adjustments to min.Turn TV on and adjust screen slowly for each gun (I would start with Red first ) when you came to point that you see red background with white lines across, at that point G2 is too high (that will cause TV to shut down,don't worry just lowered adjustment and turn tv back on) so adjust to proper voltage and do the same for each gun.After that, adjust focus for each gun (again all controls are on High Voltage Block and HVB is mounted on front of your tv after you take speaker gril out) black box with 6 controls' screen RGB, focus RGB .
You should do that in dark room in order to get perfect Black&White scale,when all guns are adjusted properly you will see grey picture.Make sure 'Color" adjustment on your display is down to 0. Another step is convergence adjustment ,Flash Focus etc.If TV stil shuts off after all, your Red picture tube is short inside,take crt pcb from tube,make sure TV is unpluged from power before that, and turn Tv on .If stays On tube need replacment...good luck)

first u check RED cathode voltage, there is approximately 150 volts in RED cathode ..if voltage ok than dry soldering all pins of CRT Base,

The adjsutment that you turned down was the G2 voltage to the red tube which is just a temporary fix for a CRT which has a short developing in it. Try turning up the red adjustment again only slightly to see if the red CRT ( tube) will light up
if it does and then the set shuts down its most likely the red CRT which is bad . If it lights up but you get retrace lines but doesnt shut down it possible that its the CR board ( Red CRT Drive Board) which is at the very bottom of the red tube.

u shoud reset your setting try to on

hi there,
if you are familiar with electronics you can do this :adjust voltage at hight voltage block it has screen and focus written on it and comes from flyback transformer,but be careful cause it can be to dangerous if you touch something else,ah,ah adjust only the one that says screen and has a R on top,that means red,ok,thanks.

check the R.G.B voltages at the crt base.if it is ok the crt may be defective.

G2 = screen...On the screen controls behind the front grill, behind the hardboard. 6 pots, 2 rows of 3 pots. 3 for focus and 3 for screens. 1 for each of the the red, green and blue guns/crts.
To adjust: Run set, change to black screen with tv/video button. Dial each screen clockwise untill you see a color. Then counterclockwise slowly untill that color goes black, then stop. Do this for all 3 screen controls.
If you need to adjust the focus then bring up lettering. I use the QVC channel for this. Focus is done by eye.

Hello paulaspec,

You have a problem with the three factors, and they are screen voltage, focus voltage, and control (focus 2) voltage. Basically these voltages have to be adjusted since the components in this section have aged some. These controls are usually located in the television on the IHVT (Integrated High Voltage Transformer) or as it is also called the flyback transformer. these controls must be adjusted together, along with the color controls. Here is how the adjustment is done (You will need a schematic diagram, a DC volt meter, and a color bar generator to do these measurments):

 

1) turn color and tint fully counter clockwise until you have a black and white picture.

 

2) connect the color bar generator to the TV (ch 3) and turn it on, you should see bars in various shades of gray

 

3) adjust as best as possible the color and tint controls to obtain the color bars on the screen Red Green Blue.

 

4) measure the voltages on the focus, screen and control grids of the CRT and match them to the schematic digram measurements.

 

5) adjust the focus screen and control grids to match the ones on the schematic diagram

 

6) once this is done then you adjust the color controls once again to obtain the red green and blue bars on the TV screen.

 

This should help if the CRT (picture tube) electron guns are still good and if the flyback transformer voltage supply is working.

 

However if you do not have a background in electronics please take the TV to a shop for repairs.

 

I hope this helps,

Thank you,

Shuttle83

how to lower the red screen voltage?