As I understand it, I have the 8840A manual, not the 8840A/AF. However, I’m not entirely certain, as the manual does not specify which model it pertains to (I couldn’t find a reference to the model, and the front page is missing).
1) Test Points (TP601 to TP607):
These test points are not labeled on my board. However, I found test points that reference voltages matching those specified for TP601–TP607. Based on this, I’m using these points for testing. Please see the attached image for the measured voltages.
2) Shorting the Inputs:
Does this make any difference? No, it doesn’t appear to have any effect.
3) Current Ranges:
Pressing the mA DC (second-to-last white button at the top) twice results in no number being displayed. (Only blinking S at the top of the display). Pressing mA AC (the last white button at the top), the display shows 30 (error).
Available equipment:
- Digital oscilloscopes (100 MHz) and analog
- Measurement was done with a Gossen Metrawatt Metraline DM62. I additionally have stowed away a Metrahit World, Metrahit Xtra, and a Fluke 87, as well as a Fluke current clamp meter.
- DC power supplies and frequency generator (up to 100s of kHz, I think, stowed away as well)