[R-390] R-390 won't power up...

[2002tii]

Terry,

As others have suggested, the most likely problem is a discontinuity 
in the transformer primary circuit.  The easy way to test this is to 
attach an ohmmeter to the two prongs of the power cord (when it is 
DISCONNECTED from the AC line) and turn the power switch on.  You 
should see a resistance equal to the primary resistance of the power 
transformer plus the line filter and fuse.  My 390A reads about 1.3 
ohms.  Anything much above that is cause for concern.  If you get 
about 1.3 ohms, then the power cord, line filter, fuse, power switch, 
connector P111/J811 (note the jumper from 3 to 4 at P111), the 
connections at terminal block TB801, and the power transformer 
primary are all OK and your problem is on the secondary side of the 
power transformer.

My guess is that you will see much greater than 1 ohm, indicating 
that one of the above items is open.  (If you had power through the 
transformer primary, it is likely that at least one of the 
secondaries would be working.)

Best regards,

Don


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