Got this unit for free recently, and decided to do a teardown. It is functional, but the buttons on the unit are absolutely terrible (hard to push, don't stay pushed, etc etc). Even after some contact cleaner - need to do a bit more work on that.
Click the image to embiggen.
The inside gets the "whole lot of nothing" award, presumably for the battery option:
Power supply, note the internal voltage range switch:
The actual counter is tucked behind the front panel:
Removing the knobs (which had the set allen screws very stuck) shows the main board. Random note: the fat left 7-segment is inverted in order to put the "dot" next to the gate indicator on the front panel. A second LED is added for the Overflow indicator. The far right dot is used to indicate microseconds, and kilohertz just is indicator-less. Thats some creative cost cutting!
I miss old package markings sometimes - a transistor:
I can't find a datasheet on the main IC
The frequency reference / oscillator with the tuning adjustment.
There are a number of these resistor packs throughout the board:
I'm also unsure of what to make of this fuse - looks like a cotton string wrapped element with a spring? First I've seen of this particular construction.
Main pass transistor of the power supply: