Hello. Tried doing a lot of troubleshooting on my 61H70. Have normal
Sound, but no picture at all. CRTs don't fire. Probed various points.
Have 220v coming into the CRT Drive boards. Have at least 170v at pin K
of each of the R,G,B board's V901, V902, V903.

Here's where I'm suspecting the problem. The nominal voltages shown on
my schematic (if I'm reading the RED voltages next to the pins
correctly) shows that R , G, AND B lines of the 7 pin connector of the
CRT -D/G board should be at around 3.0 volts. I'm reading 1.5V. Traced
these lines back to the SIGNAL/CONV board's Q510 VIDEO CHROMA IC
(56-pin, ta1316n or ta1276an) and pins 41, 42, 43 (B, G, R
respectively) should all read around 2.5 volts. I'm reading 0.7 volts.
Did a couple of readings on other pins on this ic and seems to read
normally (eg: pin 30 reads 4.5v as it should).

Question: is this Q510 ic typically the cause of this type of problems,
or could the other parts around this ic cause it? I would be grateful
if any of you technicians (or handymen) who have worked on 61H70,
61HX70, 50HX70 and similar models would share your experiences.

Thank you!
Steven L.