Hey guys,
To keep from diminishing my 330AB22 in my KV-1220U to ill fated doom, like the one in my KV-1200U, I want to disable the instant on feature. The two blue wires carrying the 6.3v feed from the transformer I believe should be untouched, but kill the feed to the tranny. Would this be the best way, and can i break the feed from the power switch? I looked for threads about this but couldn't come up with anything concrete.
Thanks
Shawn:thmbsp:

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I'd have to look at the schematic, but I might suggest re-thinking the reasoning for doing that. It has been discussed before, that keeping a low voltage on a CRT at all times, actually prevents damage. Letting it go cold, may in fact cause the gasses in the tube to attack the cathode coating quicker, and ruin the tube faster. Several CRT engineers seem to think the same, and I've had good luck with keeping 2 or 3 volts live to the tube in various sets with weakening tubes. It seemed to keep the tubes from getting worse.

Charles

ctc17, radiotvnut and I personally saw some instant-on sets that had been plugged in for over thirty years and the CRTs were still nice and bright. Before that I would have been concerned about it, but not so much anymore.

Some if not most instant-on TVs had a diode shunting the power switch which ensured the tube filaments always received a small amount of voltage while the set was off, so warm-up time was cut to a bare minimum (a few seconds as opposed to a minute or more) when the TV was powered on again. Removing that diode will ensure that the set is completely off when the switch is in the off position. However, if this is done on a TV with a remote or any other system, such as an on-screen clock and/or channel display, that requires the power to remain on (in the form of a small voltage to sustain the memory systems) while the rest of the set is off, these systems will revert to their factory defaults (in the case of OSD electronic tuners, the tuner will reset to channel 2; with OSD clocks, the display will simply disappear) as soon as the power is removed and will have to be reset when the TV is turned on again.

Using a large resistor in the filament supply to achieve instant-on is a new one on me. I don't know if this was used by only one manufacturer (the rest using the instant-on diode I mentioned) or if it eventually replaced the diode in all TVs, although most if not all of the instant-on sets I saw in the '70s had the latter. This worked well and served the purpose; however, if the TV was not unplugged during an electrical storm, lightning could and often did short the instant-on diode, creating a direct short across the power switch which locked the latter in the on position. The remedy is to remove the shorted instant-on diode, although of course this eliminates the instant-on feature. Many people saw this as a blessing, as in the '70s there was a huge emphasis put on saving energy; many viewers thought an instant-on TV was wasting electricity because it couldn't be turned off entirely. Some people may think today's televisions waste power while off as well (with the small voltages used for memory backups and the like) and could be reverting to the old habit of unplugging the set when it is not in use. These people probably do not care that the channel is reset to 02 or the clock disappears when the TV is plugged back in; all they are concerned with is conserving energy. Many people don't even bother setting the OSD clock on a modern TV or mapping the channels as long as the set works when it is plugged in and turned on. To them, installing the set is simply a matter of taking it out of the box, putting it on the stand in place of the old set, connecting antenna/cable and power, then turning on the set and watching a program, the on-screen clock and channel display being ignored; it disappears anyway, after a few seconds, and most people have other clocks in their living rooms (or wherever the TV is installed), so an on-screen clock is unnecessary.

I don't know if it is the best way, but the easiest way to disable it would be to just unplug the tv...

Power Strip seems easiest.

I think that maybe I wont modify the circuit. I measured about 2.2 V to the filiments at standby. If I want it off, then unplugging it will work for me.

what I have taken to doing is using a IR remote switch, the kind you plug into the outlet and then it has an outlet on it. After all to maintain my couch potato status I must keep from getting up and down to turn it off. Kills two birds with one stone, remote and no instant on.