06-11-2016, 02:58 PM
(06-11-2016, 02:49 PM)morzh Wrote:(06-11-2016, 01:51 PM)Tgace459 Wrote:(06-11-2016, 12:15 PM)morzh Wrote: The simplest check is, put the ohmmeter across the AC plug, while Off. Turn it on. The resistance should be on the order of a few hundred ohms or less . If very high (Kohms, Mohms), your filaments are open or the tube sockets do not make good contact.
Simplest test first...
I have an "auto range" multimeter that automatically sets the range ( I can also set it to manual range if I wish).
If you mean from spade to spade...when I try this it starts out with a 0 reading and when I turn on the power switch, the display cycle up through a series of Mohm readings 18...19...then returns to 0.
Thing is it doesn't to it every time I turn the switch off then back on again and switching to "manual" and testing various ranges give me 0.
If I test from the + spade to chassis I get 0 when "off" and .474 mohm when "on".
This does not make sense. What you are telling me is you have a short circuit between the plug terminals whether Off or On.
Yeah. im not sure whats going on there. I thought maybe something was "up with" my meter, but it tests resistors very accurately (when I test new ones out of the package).
And to be accurate. The result is not actually zero, as when I touch the the probes together (0.00). It's going back to the "no read" screen (0.L).
I'm using a salvaged cord from an old computer power-supply (two prong).