[Hallicrafters] SX-28A power supply problems

[Bob Young]

I bought an SX-28A a few weeks ago, it worked fine until I decided to ground 
the ground lug on the back with it tied to A2, it then immediately blew a 
fuse and also blew the return wire going from the switch back to the 
transformer. It now has very low volume you can only hear with headphones 
near max volume and only will pick up very local stations. It has a low hum 
you can hear in the headphones in receive position and nothing in send which 
I assume is normal. It is virtually dead, I am almost positive the power 
transformer is ok as I get B+ at C48 or C49 (not sure which is which) with 
it in receive and 0 with it in send.
Come to find out someone tied pin 5 and pin 1 of the shorting plug together 
on the back of the receiver, but the send-receive switch also grounds this 
line, it's the B+ wire, I assume also that this was an alternate 
send-receive switch that was tied together?. I haven't checked CH1 and I'm 
not sure whether I checked C49 or C48 as it is so tight down there, I assume 
my next logical thing to check would be CH1? I'm also thinking that because 
the return wire from the AC switch opened that perhaps it was pinched and 
grounded to the chassis, the chassis was live and no one ever grounded the 
thing before, but I saw no scorch marks on the wire but it was definitely 
cut, melted or blew apart. any help would be appreciated,

Bob Young
Millbury, Ma.