Cleaning leaked electrolytic & corrosion on PCB

some

potential

liquid

litmus test first to see of acidic or alkaline and go for the opposite as cleaner ?

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

If you can beg or borrow an ultrasonic cleaner, ordinary water with a dash of washing up liquid will do fine,

Any crystals or ceramic resonaters should be removed before ultrasonic cleaning.

If the construction of any components mean they trap water, a second dip without detergent will be needed, and you may have to bake the board to dry everything - the pre-heat phase on a SMD oven should do it.

I scrub with white vinegar and a toothbrush, then rinse with alcohol. If the corrosion is more severe, mechanical methods may be needed, Scotchbrite type cleaning pads work well but you have to be careful not to damage fine traces. In some cases it's best to neutralize and then clean off as much residue as possible and then leave the remaining corrosion alone.

Dishwasher.

John

You must be single.

"N_Cook" wrote in news:hpqhja$apo$ snipped-for-privacy@news.eternal- september.org:

use vinegar if an alkaline electrolytic,or sodium bicarbonate(baking soda)solution if acidic. then rinse well,prferably with distilled water,then some 90% isopropyl alcohol to dry.

use a cotton swab soaked in one of the solutions to test it,then try the other on a new swab.

vias would probably wick up the solution by capillary action.

The electrolyte is mostly a weak organic acid. Neutralizing it with any manner of mild base will prevent further corrosion. I use household cleaner, such as 409. You can tell that it's working if the liquid foams slightly on contact.

The trick is not neutralizing the electrolyte. It's cleaning up the mess afterwards. I smear the residue and "suds" around with a paint brush, wash with water and/or alcohol, and then use compressed air to blow as much of the liquid away (so it will dry quicker). Canned air doesn't work well. An air compressor and nozzle work just fine.

No. It will leave an oily residue that will eventually turn into a big mess when the dust lands on the oil. It's also kinda expensive for washing boards.

Obviously, there's no need to supply a Tek model number. Many such pieces of test equipment are very sensitive to leakage caused by board contamination. For such boards, you may need to give it an alcohol bath, possibly several times.

David Eather wrote in news:f-OdnQDYA-OYfF3WnZ2dnUVZ snipped-for-privacy@supernews.com:

I've used my dishwasher and Calgonite to clean 2236 DMM boards,then a drying session in our TEK field office's drying oven at around 140DegF for

You can always do it while the wife is out, it's not gonna damage anything.

When I was a teenager I occasionally washed engine parts in the dishwasher, not something I'd recommend, but my mom never found out.

Just be sure to do a 60 C bake for about a half hour afterward.

Hmm, you bought a TDS5xx? There is a lot about cleaning these board on the Tektronix user forum on their website.

Excellent advice. A household dishwasher (with the normal powder detergent) is an extremely cheap and powerful cleaning device for almost anything. It took me a while to convince my ex-lab to use one for cleaning larger UHV parts rather than an appropriately-sized ultrasonic tank which would have cost the equivalent of 100 dishwashers. There are things that a dishwasher isn't good enough for, but they are few.

robert

It was a different story the one time I put a pan of trichloroethane on the gas ring!

Many TDS 6XX scopes also had this problem. I run them through a dish washer first, then a Simple Green scrubbing followed by rinsing and blow dry using a compressor. After that I scrub 'em again with isopropyl alcohol, remove all the caps and replace with new ones. If it still doesn't pass it's diagnostics and SPC, start looking for open vias (usually black) and etches that are close to the areas where the worst of the leakage was.