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While flipping through channels last night my TV went blank. I can now get sound, but no video. I have done some troubleshooting, but this is not my area. Please help me fill in the blanks.


When I turn the TV on, I get bad video for about 5 seconds, then just sound. The standby light on the front then blinks 5 times. After downloading the service manual, this is what I know.


White Balance Failure:


Video out (IC3701, 3801, 3901) is faulty. (CR, CG, CB)

CRT drive (IC3006) is faulty. (A board)

G2 is improperly adjusted


I removed the back covers to see if anything obvious was bad. I don't see anything burnt or smell anything. The following is what I do see, and think for someone who deals with this, probably tells alot.


When powered on, I can hear a click as the TV starts to warm up. The blue and green lights then turn on brightly. At the same time, the red light slowly lights up. It will then flicker a bit before all 3 lights quickly turn off with a very quick flash of light.
 

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:EDIT: I only read half of your post before replying. the shutdown thing is the only thing that the Kine bias doesn't normaly do. HA, so the rest of this post can be disregarded, or read for pure interest.


Sony TV's use a "Kine bias" circuit that monitors current draw from the picture tube(s), if this current value falls out of a prescribed threshold then the picture will blank out, sound remaining. Usually the tv set will be slower and slower to turn on, or they will start blinking, eventually losing the picture complletely. There is only a temporary fix that may last a while , that is turning down the brightness and contrast until the picture stops blinking. You can also fiddle with the screen voltages but that can throw off your gray scale.


Usually you will end up needing at least one new tube... sometimes you can't even tell which tube it is so you end up swapping out all three



expect a +$500 repair in the near future unless you have a warranty.


Hope the info helps!
 
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