VFD display on my Keithley 2400 is not turning on, and there were no visible signs of damage.
I get 5v on the display board supply header and IC's but there is nothing on the 37V supply header for the display, nor is there any high voltage supply going into the display driver IC's.
The manual also mentions that the VFD is supplied with 60VDC and 5VAC directly from the digital board,
which are supplied by U625 but this does not exist on either the digital board or the analog board
(as far as I can tell, it is neither mentioned nor shown anywhere else in the service manual or on the physical board.)
I read correct voltages on TP5 - TP9 on the digital board.