[Test-Equipment] Kikusui Freq. Counter problem

[Steve]

At 04:58 PM 1/20/2020, Howard Weeks wrote:
>Bob,
>
>If the boards are mounted in sockets, try removing them one at time, 
>wipe the contacts and replacing them. I have a lot of HP and 
>Tektronix test equipment that has seemingly went crazy at times. 
>That has fixed mine every time over the last 10 years or so.
>
>I would guess that the board contacts are trying to corrode on me.

As well as corrosion, closely-spaced traces on the PC boards can also 
be growing conductive "whiskers". You cannot even see these things 
except under a microscope but after so long a period of time, they 
are a definite possibility. Thus, merely removing and reinsertion of 
the board may not be enough; you may also need to clean the board 
traces to wipe away these lil gremlins.

I got shocked while working for a former employer when we got a 
contract to examine some power supplies specifically for "whiskers". 
I looked them over closely, even with a big magnifying glass under 
high intensity lamps, and declared them "clean". The customer wasn't 
convinced, however, and had us submit the supplies to another 
laboratory for microscopic examination. The lab that did that work 
sent back photos of "whiskers" growing all over the PC boards of the supplies.

SteveH K0XP