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Philco model 42-1012 power problem
#16

Did you check the power cord for continuity? One end should go to the power switch and the other to one end of the transformer primary. How about the power switch itself? If you read nothing between the plug and the power switch then the power cord is likely shot, at least at the plug end. If you read something then check across the switch as mentioned before. Another thing you could try is to bypass the power switch by shorting across it with an allegator clip test lead, or by soldering a length of wire across it.
Generally speaking if the transformer is bad it will smell and appear charred along with tar dripping out of it. All of the other windings check out except the primary so either the primary winding is open or something between it and the power line is open, since power transformers rarely fail on the primary side with anything short of a lightning strike and it is not uncommon for an old radio to have a rotted power cord or one of these Philco models to have a bad power switch I would bet against the transformer being the problem.
Regards
Arran
#17

Arran Wrote:Did you check the power cord for continuity? One end should go to the power switch and the other to one end of the transformer primary. How about the power switch itself? If you read nothing between the plug and the power switch then the power cord is likely shot, at least at the plug end. If you read something then check across the switch as mentioned before. Another thing you could try is to bypass the power switch by shorting across it with an allegator clip test lead, or by soldering a length of wire across it.
Generally speaking if the transformer is bad it will smell and appear charred along with tar dripping out of it. All of the other windings check out except the primary so either the primary winding is open or something between it and the power line is open, since power transformers rarely fail on the primary side with anything short of a lightning strike and it is not uncommon for an old radio to have a rotted power cord or one of these Philco models to have a bad power switch I would bet against the transformer being the problem.
Regards
Arran


Hi Aaran,
Did all those tests.
Have ruled out the switch.If I ohm it out with the radio unplugged,it seems to work fine.
Do you know where I can find a wiring diagram with color codes and voltages for the primary,sec.,and filament wires.
SOmeone has replaced this tranny before.Wonder if they screwed up when they wired it?
There is tar leaked out of the tranny.Kind of made a mess out of the wiring under the tranny.I know the part number on the tranny is different from what the book says it should be.
I can see where someone has done some work on this before due to some sloppy soldering.
Would still like to find another working chassis.
Thanks for the info.
murf
#18

Problem solved.
Got a 1013 chassis,and everything looks great.
Even have power as it should.
Now I have a use for the set of caps that I bought.
Apparently someone had a problem with the off switch.Looks like the little finger that actuates it is broken.So instead of tearing it apart and replacing it,they unhooked it and replaced the volume switch with a combo on/off/volume switch.Works great.
Got plenty to do this weekend.
murf
#19

OK guy's.
Here's what I found with the used 1013 chassis.
Powers up fine.All tubes light.All lights work.
Hooked it up to the speaker and tried again.
Just get a hum.No stations received.
Volume works good.
Looks like new caps for sure.
Have to look at the coils too.
Wish me luck.
murf




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