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Vertical retrace lines is the problem. Thin white lines runs across the entire screen, at about an inch apart to each other. Check its video output supply voltage. Reduce the screen voltage to a little bit down and check. If you still wish to know more about this fault, check this site. Pull up older posts there.
if retrace lines at top of picture the issue is in the vertical circuit--usually a bad filter cap and or the output chip (most of the caps that cause that are 220 uf or 330 uf and connected directly to one pin on the chip.
If retrace lines are across entire screen---likely the master screen control on the Flyback is set too high--causes excessive brightness and the retrace lines.
Chances are you should have checked some components related to that IC,namely an electrolytic capacitor.They tend to leak or short.That IC burned for a reason.
Oh dear ! I fear my answer may not be what you want hear but my advise is free. Bright green raster with Flyback (retrace) lines may indicate a heater cathode short in the tube (crt) this causes a sharp increase in beam current and the power supply shuts down into standby mode. To prove the point isolate the red and green cathode pins on the tube base and cross couple the red video output stage to the green cathode pin and the green output to red cathode pin using wire links. If set now comes on with bright red raster the fault is in the green video output stage and not the tube. If still bright green then tube is most likely cause. Gently tapping the tube neck may prove the point, but take care the tube neck is thin glass and if hit too hard will break compounding your problems. WARNING if you do not feel totaly confident to attempt this level of repair there is no shame in seeking the advice of your local service technician. Safety first always
check the high voltage with the screen control turned up high where there is no raster. suspect problem within the video circuit where there is no high voltage or defective picture tube.some time when the screen is black and the screen control advanced,you can see if the tv has video or vertical or horizontal problems on the screen.service the high voltage circuit if there is no raster or high voltage is seen.no raster can be caused by the no heater or filament in the CRT.----
a defective picture tube can cause many problems, such as, poor brightness ,missing colors,intermittent picture,poor focus,a single-colored raster,arching in the gun assembly,retrace lines in the picture,negative picture,chassis shutdown,noheater or filament lit and no raster to name a few.an open filament or heater can cause no picture or no raster symptom.a defective CRT can have an extremely bright screen.loose particles of the cathode element can lodge between the grids and cause an intermittent black and white picture. simply tap the ends of the CRT gun assembly and notice if the picture begins to flash off and on.----
with a leaky picture tube after turn on the raster dims and get extremely bright.a dim picture with no green in the raster can result from a bad green assembly. a heater-to-cathode short can cause a raster to change colour or a result in no raster at all.replace the picture tube if there is severe arching in the neck of CRT.
excessive brightness with retrace lines and a vertical collapse to a thin line can be caused by a bad coil on the neck board of the picture tube.rejuvenate the picture tube when there is very bright green screen.
check for the resistance change on the resistors of the CRT neck board for an excessively bright picture with retrace lines.excessive dust inside the CRT spark gaps within the picture tube socket can cause the very bright raster and the chassis shutdown.a defective video amp,luminance buffer,or reference transistor can cause a bright picture with retrace lines.
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a green screen on power up with retrace lines. At shut down a point appears in the middle of the screen.
Sounds like either a shorted G2 grid, or bad flyback. If a phospher flake has shorted the grid in the tube, you can sometimes have luck by using a megger set at 1000VDC, to burn away the short.
This is usually caused by the line HV going too high causing the anti-UV protection to kick in so fit a dummy load 40W lamp instead to the line output to allow measurements to be made.
how is the 200 volt supply to the video output transistors??
measure the collector voltage of the video output transistors with the crt board on and off the crt. if voltage goes up when crt board is off then crt shorted
From your description of the problem, there seems to be a Cold solder in the Vertical Oscillator or Deflection Coil circuits. If you know Solid State electronics, and are good with a soldering Iron, sure u can do this yourself. U
gotta trace the Vertical section components and locate the cold solder.
In most cases it will be a loose connector from the Deflection coil to
the main PCB.Also check for the soldering of the Vertical output IC.
could be but there are a few checks that need to be donr first.. Try to turn down the g2 control just a bit on the flyback transformer. If no effect unsoder the blure drive transistor on the crt board If the blue is still there that means the crt is shorted and you could try to clean the elements with a crt rejuvenator and see if that helps. If the screen goes to red and green after you disconnect the blue drive transistor then you need to check the osd drivers as well as the rgb output drive from the video IC. If the blue gun in the tube shorted or leaky I have in the past and it really works a isolation transformer that plugs in to the crt socket and the other end plugs into the crt. What this does is isolate the the gun of the crt from the filiments and thats where they get shorted or leaky but for how long it will last who knows.
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