The author didn't specify a short between the 2 power input sides.. what he
stated was continuity (and his native language isn't english).. it's also
not exactly clear what type of equipment he's using for testing.

Diode D7 is physically close to the power connector, and its designation 7
suggests that it's electrically near the connector.
If the diode is shorted across the DC supply, one of the conductors in T3
would open if unable to handle the current.

D7 may not be across the DC supply, and not have anything to do with the T3
failure.. that's up to the person testing the unit to determine.

--
Cheers,
WB
..............


"tm" wrote in message
...

Don't forget that there is a short form B-C.