One of the first things to check is the diodes in the rectifier bridge.
You may have an open bridge.
When you plug in the supply, and turn it on, do you hear hum in the
transformer? That would validate the transformer as receiving AC
power. You may have to put the ear next to the supply to tell.
The buzz might also indicate a capacitor was about to go; you pretty
much have to do some point to point voltage measurements to find out
what is wrong. You can half split a problem by looking for DC voltage
right after the bridge rectifier ta the plus side of the first filter
cap. Then, if you have voltage there you move toward the output, which
might mean the regulator went. If you don't have voltage at the plus
side of the first cap, look back toward the bridge rectifier and
transformer.
Not getting a pilot light might indicate an AC side problem, but if the
pilot light is 12 volt type, it would be on the 12 volt bus, which is
probably closer to 13.4 normally.
These steps are general steps that work with any power supply circuit.
But, if the 262M is a switcher, there could be other feedback paths that
could shut down the supply. A schamtic is very helpful.
-Stuart Rohre
K5KVH
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