EEVblog Electronics Community Forum

General => General Technical Chat => Topic started by: iampoor on May 12, 2016, 11:27:42 pm

Title: Cleaning dog pee off circuit boards.
Post by: iampoor on May 12, 2016, 11:27:42 pm
Just got a tube amplifier in for repair today.

It is a guitar amp. Apparently, the band was auditioning a new drummer, when the drummers dog got on top of the amp, and peed in the vent. It leaked in around the power tube sockets, and shorted out the power tube cathode resistors.  :-DD

Anyone ever had to remove dog pee from single sided circuit boards? I am worried since it is clear, and I cant really see it. The smell is VERY strong however.

This is why I like being a technician.  :-DD
Title: Re: Cleaning dog pee off circuit boards.
Post by: uncle_bob on May 12, 2016, 11:36:54 pm
Hi

Get the best quality DI water you can find and spray it down. Blow off all the water you can. Dry it off in a warm oven. If that does not kill it all, switch to electronic grade isopropyl. Check that it does not attack the plastic first.

Bob
Title: Re: Cleaning dog pee off circuit boards.
Post by: MadTux on May 12, 2016, 11:40:06 pm
Get another dog around.
As soon as he stops pissing onto the amp, you did a good job in cleaning it  ;D ;D
Title: Re: Cleaning dog pee off circuit boards.
Post by: Muttley Snickers on May 12, 2016, 11:48:02 pm
Sounds absolutely disgusting, I would be inclined to take it out the back and hit it with the pressure cleaner and then dry it off with the oxy torch just to send a message not to send me this shit again, otherwise plenty of IPA and a paintbrush and then a good hit with IPA and a fresh paintbrush just to be sure.

I remember once going to a residential site to run some cables and install some gear and as soon as the client opened the front door I almost vomited all over her, the joint was full of cats and the residents couldn't smell it or had adapted to the disgusting odour, a two hour job took me six because I had to constantly go out for fresh air and dry reach every few minutes, eye watering stuff and I never did like cats much.
Title: Re: Cleaning dog pee off circuit boards.
Post by: Andy Watson on May 12, 2016, 11:53:11 pm
I've had to repair Hi-Fi  that the owner's precious cat has claimed as it territory - horrible stuff!  Glad I don't have to do that sort of thing any more.

Will dog urine show-up under UV light?

Title: Re: Cleaning dog pee off circuit boards.
Post by: alsetalokin4017 on May 12, 2016, 11:54:11 pm
Sounds absolutely disgusting, I would be inclined to take it out the back and hit it with the pressure cleaner and then dry it off with the oxy torch just to send a message not to send me this shit again, otherwise plenty of IPA and a paintbrush and then a good hit with IPA and a fresh paintbrush just to be sure.

Sure, that will take care of the dog... but what about the circuit board?
 :-DD
Title: Re: Cleaning dog pee off circuit boards.
Post by: AF6LJ on May 13, 2016, 12:00:04 am
I have some experience in this;
409 works really well lots of water and dry everything off really good.
Title: Re: Cleaning dog pee off circuit boards.
Post by: edavid on May 13, 2016, 02:00:42 am
If you go to any pet store, you can buy products intended for just this purpose... enzymatic cleaners like "Nature's Miracle".  Soak the board in that, then rinse with water.  Repeat if necessary.
Title: Re: Cleaning dog pee off circuit boards.
Post by: IanB on May 13, 2016, 02:31:07 am
Tube amps are supposed to contain HT supplies. The dog is supposed to get a surprise when he pees into it. I think the amp was defective before the dog got to it  ;D
Title: Re: Cleaning dog pee off circuit boards.
Post by: mtdoc on May 13, 2016, 02:53:15 am
I guess the dog did not like the band...

Urine shouldn't have anything in it that is not water soluble. I agree - a good soak and rinse with distilled or DI water should do the trick. If not IPA will.
Title: Re: Cleaning dog pee off circuit boards.
Post by: Tinkerer on May 13, 2016, 03:13:51 am
Sounds absolutely disgusting, I would be inclined to take it out the back and hit it with the pressure cleaner and then dry it off with the oxy torch just to send a message not to send me this shit again, otherwise plenty of IPA and a paintbrush and then a good hit with IPA and a fresh paintbrush just to be sure.

I remember once going to a residential site to run some cables and install some gear and as soon as the client opened the front door I almost vomited all over her, the joint was full of cats and the residents couldn't smell it or had adapted to the disgusting odour, a two hour job took me six because I had to constantly go out for fresh air and dry reach every few minutes, eye watering stuff and I never did like cats much.
Thats the sort of thing where its time to call animal control. If you take care of cats properly and keep things clean(disregarding the hair hair everywhere) they should not stink that badly. Unless of course you go up to the litter box.
Title: Re: Cleaning dog pee off circuit boards.
Post by: bills on May 13, 2016, 04:29:38 am
Open it up wash it down and leave it in the sunshine for a few days all will be well. ( at least that works with mouse nests and cat pee in old tube radios ) Valve for the rest of the world.
Title: Re: Cleaning dog pee off circuit boards.
Post by: Brumby on May 13, 2016, 04:54:16 am
I only had one similar experience.  It was an old TV that had mice through it.  Rinsing with copious amounts of water in the backyard, followed by a nice sunny position for a week to dry out ... and then another to be sure.  Some IPA and another few days before I was game to power it up.  It worked.
Title: Re: Cleaning dog pee off circuit boards.
Post by: iampoor on May 14, 2016, 08:24:35 am
Thanks for all the suggestions!
I am in the middle of trying commercial urine cleaner, IPA, and DI water. I think I got most of it off.. The 409 didnt seem to like these boards too much. Oh well.

The tube shorted between the heater and plate....left a large burn mark and gouge in the board (Along with some lichtenburg patterns!) It measures ~10m between heater and plate on the PCB. I am thinking of drilling some isolation slots if I cannot improve that with more cleaning....

Sounds absolutely disgusting, I would be inclined to take it out the back and hit it with the pressure cleaner and then dry it off with the oxy torch just to send a message not to send me this shit again, otherwise plenty of IPA and a paintbrush and then a good hit with IPA and a fresh paintbrush just to be sure.

I remember once going to a residential site to run some cables and install some gear and as soon as the client opened the front door I almost vomited all over her, the joint was full of cats and the residents couldn't smell it or had adapted to the disgusting odour, a two hour job took me six because I had to constantly go out for fresh air and dry reach every few minutes, eye watering stuff and I never did like cats much.

wow, yeah thats extreme...thankfully this was jut a small mess! Plus its for a good client.  :-+
Title: Re: Cleaning dog pee off circuit boards.
Post by: PA0PBZ on May 14, 2016, 09:01:46 am
I'm a bit late to the party but still... My sister once had a VCR and a cat that didn't like it, when opened you could see the crystals on the pcb  :( So I gave it a good hot shower, let it dry for a good time and it worked again :-+
Title: Re: Cleaning dog pee off circuit boards.
Post by: Muttley Snickers on May 14, 2016, 09:31:49 am
Thanks for all the suggestions!
wow, yeah thats extreme...thankfully this was jut a small mess! Plus its for a good client.  :-+
I actually added another detailed post after the one you have quoted regarding that particular job but shortly after decided it was probably best removed as it was rather disturbing and so was the experience, this was extreme and the stuff of nighmares. 

Favours for friends, family and good clients can be very rewarding but on occasion also the most taxing, I'm lucky nowadays to be able to choose what we take on and what we don't.   ;D