Cleaning scope front ends?

[cj555]

 Hi everybody – I have a digital Tek scope that seems like it was in a dirty environment.  When I got it there was a kind of oily gritty film covering the inside services, not real thick but definitely noticeable. I've cleaned it off most of the board, and that seems to of helped a couple of issues.

But I seem to recall  someone discussing on a video why you should be really careful and never even touch those sensitive components, oils from your finger etc. they may have any details or links about that? (Dave very well may have discussed it, or maybe it was Signal Path. Pretty sure it wasn't Mike though! He often doesn't  seem to be as gentle with stuff :-).  )

 Or recommendations  on cleaning, leave alone, do it carefully but then assume I'd  have to recalibrate, etc.?

Thanks!

[Karlo_Moharic]

Use rubbing alcohol and Q-tips. Rub gently and let it dry good before plugin it into outlet

[bd139]

As for why, Skin oils and other crap has a relatively low resistance compared to air so when it gets on high impedance areas it tends to cause all sorts of weird measurement errors.

IPA recommended here too. I use one of the wife's horse hair paint brushes (new - don't tell her) and lint free cotton cloth.

[JFJ]

... recommendations  on cleaning, leave alone, do it carefully but then assume I'd  have to recalibrate, etc.?

There are some useful tips about PCB rework, repair and cleaning, in an old HP Bench Briefs article:

http://www.hparchive.com/Bench_Briefs/HP-Bench-Briefs-1982-07-10.pdf

The PCB cleaning part starts on page 8, but 'To Clean or Not To Clean' is briefly discussed on page 7.

[bd139]

I think I actually read that once. Good reference!