thermistor question

[worth]

Looking at this schematic, there is a thermistor , (Thm1) in the upper left corner between the power receptical and the power switch. Someone has jumpered this thermistor with a wire. Could that cause a problem ? There is quite a hum in the amp.

[phsyconoodler]

That won't cause a hum.You have other issues.Find those first and then get a new thermistor.

[worth]

Turns out R11 , (4.7 ohm at bottom of schem ) was burned , breaking a signal ground.