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Laurie
Double Platinum Member
Canada
4854 Posts |
 Posted - 05/27/2009 : 15:03:56
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So I inherited a dead long-chip DD-3. It had a faulty mode selector switch (now fixed) and has some issues with repeat volume. All standard stuff that i'll track down in the fullness of time.
Anyway... There was a "substance" over about 25% of the solder side of the PCB that had turned the joints dull and looked like it had eaten a few of them away - to the point of being dry.
As I was cleaning the crap off and trying to resolder the joints the smell was unbelievable, and quite familiar to anyone who has ever owned cats. Yes, somnehow this board has been peed on. It is a complete mess. The corrosion is so bad that solder wont take, and flux remover solvent wont clean the black residue off.
If anyone has any ideas about how to clean cat pee corrosion off a PCB, please let me know 
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Edited by - Laurie on 05/27/2009 15:05:11 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 05/27/2009 : 15:31:16
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Hi Laurie
Welcome to the "Pee'd on by Cats" Pedal Collectors Associations. 
I recently got a Zoom 707II multi-effects unit,
that is in exactly the same state.
But with larger area that was enhanced by someones cat.
Pity it's such a nice unit, & it even has an SD Memory card slot.
An next to Boss pedals,
I have a technical & tone fondness for Zoom gear
- excluding the Zoom 505.
See if scrapping the component leads with a hobby knife or scaple,
helps the solder to wet the joint correctly.
You could also scrape off the resist in the darkened area, use some
very fine abrasive, to clean off the black corrosion, & then re-tin the area.
Then cover the newly tinned area, with some green screw anti tamper paint, or green nail polish. also works well.
But the copper may have been irreversibly changed by the chemical reaction of the Cat pee on the copper/tin/lead combination.
Good luck - PM me if you need to.
BTW - the Zoom is new relegated to the can be used for spares box.
As a side note:
The cat pee attracts baby cockroaches, check the entire pedal out in daylight with a good quality magnifier or loupe.
There were a few living happily on the Zoom 707II.
They could end up infesting your work area/room/shed/house
- without you knowing where the (little - now big) buggers came from.
Regards Dr. Bob  |
Edited by - Dr. Bob on 05/27/2009 15:33:03 |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 05/31/2009 : 15:41:35
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So far so good.
Step 1: Use a wire brush and paint thinner to clean all the corrosion and protective coating off the board.
Step 2: resolder all connections. The solder flows now because the corrosion has been removed.
Now, just need to track down why the echos are nearly non-existant. My money is on Q9.
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Witloofboer
Gold Member
Belgium
513 Posts |
Posted - 05/31/2009 : 16:13:03
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quote:
Originally posted by Dr. Bob
But with larger area that was enhanced by someones cat.
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 05/31/2009 : 17:03:20
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Nice re-work Laurie.
My 707II is still dead - It now looks like it's a Custom Microprocessor fault.
Regards Dr. Bob |
Edited by - Dr. Bob on 05/31/2009 17:06:09 |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 05/31/2009 : 18:55:42
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Sorry to hear about the 707.
DD-3 is now working - it was C34 dry.
BUT..... the feedback/effect level is going crazy. It is fine for low settings but as soon as either knob is past about 25% it goes crazy - huge reinforcing oscillations that drive the whole thing to infinite feedback square wave clipping.
Seems like there is a gain stage somewhere that is way too hot for some reason, but danged if I can find it.
Compressor/expander is working fine. All the mixing amps are doing what they should. There is just something that is letting it run away.
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DeFrag
Moderator
USA
3409 Posts |
Posted - 05/31/2009 : 21:00:33
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damn pee!?
What I think of cats...
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Edited by - DeFrag on 05/31/2009 21:03:02 |
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bassinyourface
Bronze Member
France
76 Posts |
Posted - 06/01/2009 : 17:11:34
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Hey, nice tool !!
Think I should get one of those !
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Topic |
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DD-3 and cats pee don't mix
