HP 8593E - Hard to push buttons?

[David Chamberlain]

Hi All, I just came in to posetion of a HP8593E analyser.  It powers up fine and I get a trace and all seems good so far, although I still need to find a cable to do the self-cal.

Anyway one thing that I cannot figure out is the Frequency button does nothing? The span and Amplitude buttons works. I can hit SPAN + 8 + MHz and that sets fine.

I also notice the numbers 1 and 0 on the bottom left of the numeric key pad do not work, and the others require a hard push to get to work.

So my guess is the frequency and probably all other buttons need a good clean. But I just wanted to check with the FREQUENCY button if it's not somehow locked by some system setting.

All other buttons and the wheel seem fine.

Thanks

Dave

[David Chamberlain]

Strike that.. They all work I just had to put all my weight on to them. So I guess some cleaning tips would now be appreciated.

Thanks

Dave

[GreyWoolfe]

You can simply try operating the button a bunch of times.  Sometimes this works to free up the buttons.  Judicial application of DeOxit into the switches if you can get to them should free them up.  Take care to try not to get contact cleaner everywhere.

[Neganur]

if it's the 'rubber keypad' type, don't push them too hard since it will only make it worse.
From what I recall there is some conductive liquid that should be used to refresh the carbon domes.

Perhaps someone else can remember what exactly it was.

[MarkL]

...
Perhaps someone else can remember what exactly it was.

https://www.digikey.com/products/en?keywords=cw2605

[David Chamberlain]

Thanks for the product link, I will give it a try.

Yes after pushing them a few times they are not so bad now, and they are rubber buttons.

I found a test cable (turns out n-type connectors sort of fit over bnc's ) and the unit passes self calibration and confidence test so I might have a good one on my hands.