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Originally Posted by 6GH8cowboy
Working on a TS-912 chassis (roundie). Temp clipped in power supply caps and replaced H output tubes. I have HV but no raster. The CRT cathode volts are way high and the 695 Sams shows a very spartan brightness circuit, all cathodes tied together and completely isolated video feed from the video output via a .5uf cap. The DC path is a 180k resistor on the CRT side going to the middle of the brightness control that is connected to ground and 275v . The reality is there is a neon lamp and a 10k resistor across the .5uf cap and the brightness control isn't wired like the Sams shows. The 180k resistor is a 240k 2 watt resistor. 2 watt seems a bit hefty for just biasing the CRT cathodes.
I'm going to have to pull the front controls out and chase wires.
Has anyone got an idea how this should be wired? Is there an updated schematic or Motorola update to explain this diversion? From what I have been able to peek at the brightness control is not wired like the Sams indicates. Also the neon bulb is lit. I would think this was for a discharge condition of some kind.
Look'in for some good insight on this.
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That set is a real gem! I only seen one like it. It is rare and a short production model. Looks like they used shortcuts to see how cheap they could build a color TV.
The set uses strange tubes as used in a European or British TV design.
It's worth hanging on to for awhile.
