Bad kitty!

[Electron Tornado]

A friend has a digitech multi effect pedal that his cat decided was his territory and he should mark it. The cat marked it pretty well, as about half of the PCB was well covered and the bottom plate was very corroded. Not being comfortable working with electronics, my friend asked me if I would take a look at it.

I've tried water and Q-tips, but that only get me so far. Then I was scraping IC legs with a knife blade while working under a magnifying glass. Unfortunately, this is very slow work, and there is still dried cat urine on the back sides of some of the pins on the ICs.

Does anyone have a good suggestion of what to use to clean the PCB? I'm concerned about using something that will take off any labelling on the board. The board appears to be made of fiberglass. Is there anything that is safe to immerse the board in? Is there anything to definitely NOT use on the board?



I've already given my friend some suggestions as to the the disposition of the cat. 

[petemoore]

  Toothpaste and brush.
  Baking soda.
  Electronic cleaner spray.

[Brymus]

You want something to counter the effect of the ammonia,I forget what the other caustic agent in cat urine is.
Maybe something from deoxit ?
Or flux remover ?
My old neighbor said he knew how to make explosives from cat urine
Said they taught him that in Vietnam,IDK if its true or not.

[.Mike]

You might want to look into an enzymatic cleaner. Products like Nature's Miracle contain enzymes intended to neutralize and break down pet urine without being corrosive. You can get Nature's Miracle in the pet section of stores like Wal-mart and Target, at pet stores, and at home improvement centers.

Another enzymatic cleaner to check out is Zymeaway.

Of course you would want to spot-test on a non-critical part of the board, and make sure everything is thoroughly dried when done.

Good luck!

Mike

[markeebee]

Pee or poo?

There's a question I never thought I'd ask on this forum.

[frequencycentral]

Pee or poo?

There's a question I never thought I'd ask on this forum.

Using the search facility, I see it's been asked many times before. 

[philbinator1]

You guys are sick. 


 

[Rob Strand]

Remove the board.  I would start by using hot water and a toothbrush.  Pour the water over the board, held at an angle, and let the water run off carrying the wee with it.  Repeat a few times.   Dry it off thoroughly with a hairdryer.   If you can still see remnants repeat again.

Once cleaned, clean again with board cleaner.

I'm not fond of methods that try to counteract the wee (or other) because you can never get the concentration right and the counteracting chemical usually has equally bad effect.  The enzyme stuff Mike mentioned might work but I can't vouch for it.

[emstin1]

My old neighbor said he knew how to make explosives from cat urine
Said they taught him that in Vietnam,IDK if its true or not.

i once accidentally made chlorine gas in my toilet out of people urine  ...i wonder if it's the same principle

[markeebee]

Pee or poo?

No, really, semi-serious question.

If kitty has laid a cable, that's a stress reaction and he'll need some careful rehab to stop him doing it again.  It may not be the last time you scrape that board.

Next week on pet's corner: biasing your chihuahua.


EDIT: Ooops, just saw the word "urine" in the original post. Don't mind me. 

[frank_p]

I've tried to repair the battery to 120V oscillator of my sister's boyfriend that had been ruined by his chinchilla's piss.  This is nasty: it goes underneath all the ICs, the plated trough vias, in the switches, etc...  After days of washing, probing, desolldering the ICs to look under and repairing corroded and broken traces: and the module would still not work conveniently: I just gave up.  Rememeber that the location where the piss will have more dammaging effects are the ones that are located in difficult to access locations because the liquid will be sucked by capillary action and the concentration of corrosive constituents will be greater there.  So all those places are a PITA to reach, wash and repair.  I would say: if your multieffect is full of vias, chips and corroded tiny traces: give yourself a time limit.  If it doesn't work after that, take a big break and ask yourself if your not better to forget about it.

[Top Top]

I would think a wire brush would be your friend. Scrub IC pins like you would brush your teeth - should get between some of the cracks...

[chi_boy]

Can you submerge a board??  I don't know if trim pots would be a concern or not, but if you can submerge, what about an ultrasonic cleaner with some mild detergent?  We use them at work and they work wonders with the right solvent for the application.

[PRR]

> I forget what the other caustic agent in cat urine is.

Salt?

Salt is one reason the lawn goes brown-spot where the dog pees.

There may be a nitrogen compound (other than ammonia), because I know when an old dog's kidneys are starting to fade by how the grass reacts.

> I'm not fond of methods that try to counteract the wee (or other) because

Agree.

Everything which came out as pee is somewhat water-soluble.

Electronics may be washed in pure water; just be sure to DRY before you apply power.

Take off the odd cheap bits which trap pee, won't dry well, or are too inexpensive to piddle-around with. Jacks, most switches and pots.

Use distilled water. May be good to hot-up the water and the part.

If it is crusty: soak 10 minutes, tooth-brush well, soak, brush, .... until clean. Then clean some more.

Then as Rob says, flush with flowing water; if you have any lime/rust stain in your sink, use distilled water.

Hair-dryer will get much of the water off fast. Don't be fooled, it is still wet somewhere. At home I set PC keyboards in bright sun and breeze for several days. At work I had an air duct with a good breeze right above a fluorescent lamp with a warm ballast; I usually gave it a week.

> the bottom plate was very corroded.

That may be washed in tapwater, wire-brushed, sanded, Rustoleum-ed, or re-fabricated from scrap metal.

If the PCB copper has corroded, you may have some bright-light/magnifier repairs ahead.

If this is the $99 "digitech multi effect pedal", consider what your time is worth. If a quick rinse-dry does the deed, OK. If it becomes an extended wash, re-fab, trace-jumper nightmare, you can be well past a hunnert bux of ugly labor and still not be purring.

[frank_p]

Just be sure to wash the PBC as fast as you can.  The more you wait the more damage it can cause. Not sure about the method to wash it efficiently without causing troubles elsewhere (dishwasher (?)... ,alcohol(?)...)  .  But for the copper on the pcb (vias and under the ICs), I am pretty sure that the fastest you proceed, the less damage it will likely to cause.  One thing that I also noticed is that if you have a green solder mask on the PCB: you will be able to see where the damages are likely to be, but you will not be able to determine to what depth the damage is done underneath the green soldermask, into the copper.  So, sand it: if the trace is green: keep sanding until you see copper.  You may perhaps have to sand to the bottom.  Then you'll have to do trace repair with thin wire and magnifying glass (perhaps).

[rousejeremy]

It's a Digitech. The cat knew what it was doing.

[frank_p]

It's a Digitech. The cat knew what it was doing.

Yeah, but the piss does not care about Digitech or ZVex.

[rousejeremy]

The real question is: If there's a zVex on the carpet, will a cat piss on it?

[frank_p]

My experience was with a chinchilla, so I can't tell.  But for an other of my friend, the cat pissed in his computer.  Don't know if cats are attracted do digital stuff or hot boxes, but one thing is sure for now: were not dealing with horses or elephants.

Hope you have a nice tour Jeremy!