TENMA 72-1095 Schematic or Knowledge Needed

[arattig]

Does anyone have the Tenma 72-1095 schematic? Or URL to the file?  Trying to troubleshoot this for far too long and out of ideas...

Alternatively, if someone has had experience with the issue i'm seeing that would great to hear from you.

Issue is when Line Voltage is selected, the output as measured on a multimeter, is adjustable by the variable transformer instead of directing 120VAC to the output.  When Output Voltage or Output Current switches are selected, the output is as expected, adjustable by the variable transformer.  My first suspect were the switches, these were removed disassembled and cleaned, although there was no indication of wear or tarnish.  Their correct switching was also confirmed on a multimeter.  All resistors are within tolerance, both diodes were replaced, both capacitors were replaced, no shorted windings on the primary nor variable transformers, op amp CA3140 was replaced....not many components here to be this stumped. 
Note, i was unable to positively ID one diode, it was glass, with the typical black band on the cathode, but absolutely no other markings under magnification.  I replaced it with a 1N4148, which was physically smaller in size, so not convinced this was the correct diode, however i dont believe that if this diode failed it would cause my issue.

Schematics, guidance, thoughts and general discussion welcome!!

[arattig]

Uploading my Kicad schematic for future readers.  My first attempt at Kicad, but should be very close to the actual design.

[Smoky]

I also own a Tenma 72-1095 and I can't imagine pressing the "Line" button and expecting full mains voltage at the output.

When I press the "Line" button I only expect to see the meter reflect the Line voltage to make sure that it's there and not sagging or misbehaving.

Take a scenario that you're scrolling up the voltage on a project then you accidentally touch the "Line" button and it immediately delivers "magic smoke" style full mains voltage at breaker current to the output. There is no way Tenma would design a variac that way.



Looking at the picture, every button in the circle relates only to the meter not to the output. I don't think there was anything wrong with your Variac.

[arattig]

Appreciate the response Smokey, and directions of use.  I should of thought a bit more on the intent.

Will consider this repair fixed....