Just got an old unit from an estate sale for cheap. It may be a dead unit, but will have to see. Currently it's missing the ac,DC,ground switch and I'm trying to see how to add a new one but having a hard time reading the service manual for ita connections. Any help would be appreciated. Also with identifying if the crt screen is still operational, as I do not know how to test that. Power led on the unit does light up as well.