Quote:
Originally Posted by Jeffhs
Another way to disable the instant-on feature is to remove the diode across the power switch (I think this may be what you meant by "rewiring" the switch). These diodes often shorted after lightning strikes, effectively locking the AC switch in the "on" position. Removing the diode restored the switch function, but of course eliminated the instant-on feature. It was just as well, as instant-on kept the tube filaments on (albeit at low power), which was a waste of electricity. Remember, these TVs were made in the 1970s during the so-called "energy crisis", and many people did not like the idea of their TVs effectively being permanently "on" even when not in use, not to mention the potential fire hazard. Many folks requested that the instant-on feature be disabled when other work on the set was needed.
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What you're referring to is the simple B/W portables that only used the low voltage B+ circuit and series heaters.
The color sets used a more involved switching scheme using two separate switches, one SPDT and one SPST. The SPST cut the B+ and the SPDT controlled the heaters. It seemed the SPDT side was the one that went bad.
