Triplett 850 ????

[SilvrBult]

Sorry if I'm in the wrong catagory. I have a Triplett 850 VTVM that is not responding on the ohms and ac scale. I checked the 6al5 and 12au7(both good) 1.5 battery is good
Meter will go full scale on ohms like its supposed to but when resistance is connected meter does not move
When Ac voltage is connected meter does not move off "0"

Dc works fine

New here and any help would be appreciated

 

[cowboybob]

Have you checked any of the internal tube voltages?

For instance, the filament and plate voltages. The owner's manual schematic is short on listing circuit voltage values, but you should at least see 6VAC for both tube's filaments. And, of course, they should be lighting up.

Can't tell what the plate voltage(s) should be but you might check what value AC is being supplied to the rectifier "X1", and then see if there's any DC value on the other side of X1 (I"d expect something like 150 to 250VDC).

Be careful. There are lethal voltages present.

 

[dr pepper]

Old favorite on valve stuff is wax covered caps go bad.
You'd also want to check the power supply smoothing caps.
Do you have an esr meter?, check the resistance of all the caps if so, if you havent and there arent that many consider changing them all.