Hello folks!
I have a Keysight N9310A on my bench which needs to be repaired. It powers on normally, passes all self tests.
It is a unit from 2008 so a bit aged.
Problem: Some buttons are not working (e.g. "RF on") and the "Information" screen, which should normally show firmware version, options etc., has black pixels all around and misplaced fonts.
I will post a screenshot tomorrow. It looks quite funny.
All other screens and menus I tested are showing correctly.
I have checked all supply rails with DMM & scope (glitches). Nothing unusual, all voltages are there.
The caps in the PSU show no signs of bulging.
When probing the keyboard flat flex connection to the board, most buttons show sharp transitions high/low when pressing.
Except the RF button (and others in the row like "Trigger"):
When pressing, the "edges" are like the curve of a charging capacitor (RC), very slow.
I suspect two things:
First: Possibly the keyboard, inparticular the RF-ON button has a bad contact or is dirty. This could be the button which is used most.
Second: The weird pixels and misplaced fonts all over the place in the "Information" screen might be due to bad memory maybe or a bad regulator on the digital board.
Maybe someone has a similar issue in the past
I keep you posted, thank you!
Cheers,
Bernhard