Sony KV-M1411U Video display issues

[Electronic M]

Originally Posted by Alex KL-1

Yes, is possible. Some CRT have "hot" G2. Is good to be safe/sure.
Some time ago I also had only a 600V Fluke DMM, and I needed to measure +Boost on a TV (near 900V). I carefully ajusted a attenuator asing the 600V range (on manual range) using lower voltage and a relatively robust potentiometer. then, I sub it with a array of series 1kV rated resistors to achieve correct value, and measured perfectly on the 600V range (in that time, I only made a 2:1 att; eg. 900V reads 450V).
Nowadays I restored a tube MM, using HV resistor on voltage scale divider. Resulted limited only by switch, and I comfortably use it's own full 2kV scale without any trouble.

There's another way to measure 1KV on a 600V meter. Find a 400V B+ source measure it with respect to ground and record the number, then measure the 1KV point with respect to the 400V B+ then add that value to your recorded value to get the actual value of the 1KV source....I did this once on an early SS RCA I was fixing on site with limited tools at a friend's house. It worked great. I think in my case it was a 900V boost, a 350V B+ and a 600V meter, but the same principle applies if the TV has power supply rails that are a good fraction of boost.

[zeno]

Most G-2 run off a divider. First the focus apx 6KV is dropped by high
ohm resistors off the HV. then the low side of the focus is divided out
to put the G-2 in range. Typ G-2 is 400 +- vdc.

Alex mentioned A.K.B. ( auto kine bias) & yes most Sony used it.
They also made it so the video would be cut off if the jug was weak.
I asked Sony FS tech about that & he said sony did NOT want a set with a bad pix so you get none !
Symptom usually no raster then blinking raster as it warms up.
On AKB sets if you shrink the V size a little you will see 3 color stripes
at the top. Thats the guns firing to collect current data.
A few more tricks if need be.

Anyhows I am going to cool off. Spent the morn at Hampton beach N.H.
and wow was it hot

Zeno