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 !