I had to remove BI/Beckman trimpots from our products at somewhere around 2000 because they would fail after the boards were cleaned. We switched to Bourns, and the problem went away. BI denied that they had a problem, but later they acknowledged that their O-rings were defective as they tried to lure us back.
We used an industrial circuit board cleaner, with a citrus based solvent that was diluted with water. This was followed by an overnight bake in a 105°F dryer.
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-----Original Message-----
From: "Mark Goldberg marklgoldberg@... [hp_agilent_equipment]" <hp_agilent_equipment@...>
Sent: Oct 16, 2017 9:34 AM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] Plan to deep cleaning my gear
I agree with this. I have been involved in many product developments over
40 years ( not for HP) and would not use anything but >99% IPA or DI water,
and only if the parts are rated to be cleaned with these solutions. If you
don't know if they are rated, they may be damaged. Some trimpots,
connectors, etc may not be cleanable without damage. The industry did use
Acetone and Freons, but due to safety reasons, those are much less common
now.
Mark
On Oct 16, 2017 5:48 AM, "Adrian Nicol fenland787a@...
[hp_agilent_equipment]" <hp_agilent_equipment@...> wrote:
I understand the desire to try and get the insides to look like new! Like
Paul, I guess I have 50+ bits of oldish HP and Tek equipment, but I'm not
sure I would do what you intend, especially with water!
I recall that in the 60's through to the early 80's water washable fluxes
were not necessarily used and PCBs were often expected to be cleaned with
CFCs (ICI Arklone and the like) to get the rosin based fluxes off, so some
components were not sealed and not meant to get wet!
Early PCBs often meant for hand assembly did not have a solder resist
either so there may be a small risk of moisture penetration of the FR4?
I clean things that need it, suspect areas of PCBs due to contamination,
old flux from re-work, switches and so on with IPA, dust I blow off with
the shop airline, case parts, yes soap, water and brush (and solvent where
safe and needed for sticker residue) but the 'aint broke don't fix' mantra
is my guide!
On Monday, October 16, 2017 5:26 AM, "Calvin Guan guancalvin@...
[hp_agilent_equipment]" <hp_agilent_equipment@...> wrote:
Hi,
I am thinking of deep cleaning of my gear. 8566 SA, 8510 VNA, 8515A
S-parameter test set, 8350/83592 sweeper.
I think I am going to remove all PCBs, soak them into clean water, brush
them and dry them with hair dryer as soon as I can.
For delicate microwave assemblies like DC, YIG, YTFM, mixer and ovenized
crystal, and CRT display, I will just brush dirt off the surface and leave
them alone.
For sticky keys, soak the keyboard assembly into IPA, rinse them and dry
them as quickly as I could.
Sounds like a plan?
Thank you!
Calvin
Michael A. Terrell
Michael A. Terrell