Worn CRT or other issue? (Sony)

[Electronic M]

If the red is stronger than the other primaries and you don't have controls to turn red down, why don't you just increase green and blue to balance the grayscale?

[grossbard]

Originally Posted by Electronic M

If the red is stronger than the other primaries and you don't have controls to turn red down, why don't you just increase green and blue to balance the grayscale?

I tried. No matter what I did, I couldn't get the grayscale balanced very well at all. According to my colorimeter, using HCFR, the red was over 150% and I couldn't get it to go down much, if at all. Also, the drive/cut controls didn't seem to have a very big range.

[zeno]

Do this. Measure the 3 cathodes (K) of the CRT at the socket & post them.
Should be abt the range of 125-150 VDC.
With AKB the way Sony did it things dont make sense. If its the CRT
you should get the pix blinking on & off especially when COLD.
A dominant red may indicate a problem in the red BUT usually would come
with thin white lines in the pix. If you can post a pix with the color
level all the way DOWN it would help.

73 Zeno
LFOD !

[grossbard]

Originally Posted by zeno

Do this. Measure the 3 cathodes (K) of the CRT at the socket & post them.
Should be abt the range of 125-150 VDC.
With AKB the way Sony did it things dont make sense. If its the CRT
you should get the pix blinking on & off especially when COLD.
A dominant red may indicate a problem in the red BUT usually would come
with thin white lines in the pix. If you can post a pix with the color
level all the way DOWN it would help.

73 Zeno
LFOD !

R - 134.4v
G - 128v
B - 127.5v

Here's a pic with the color set to 0. That moire in the middle is just from the camera.
https://i.imgur.com/8wgYpAr.jpg

I've only had this TV a few months but the picture has been rock solid, no blinking at all. I mentioned in my original post that I could see a horizontal blue line at the top that would go away after a while. Today, when I turned it on, I could see the R and G line too, along with the blue line, but they all disappeared after the TV was on for a few min.

[zeno]

OK the voltages look with in reason. So you may have
1) a very slightly weak CRT
2) something very slightly off in the red or the jungle IC.
The pix looks very good otherwise. You may want to check
all the resistors in the red from the jungle IC to the CRT.
Be sure to lift one end to check. Beyond that you could go
up in value on the red out collector resistor ( typ 18 K 2W ) a little but
leaving it alone may be the best....

73 Zeno
LFOD !

[old_coot88]

Did you try jumpering that 1.2 ohm heater resistor (R704)?