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Cleaning Old Soda Off Of A Circuit Board?

P

phaeton

Jan 1, 1970
0
Hey y'all. Been awhile since I've been here. I've missed the joint.

I might be picking up an old SS Fender bass amp from a guy at work for
dirt cheap. Like buy him a case of beer and it's mine, cheap.

Anyways, I don't know the details, but at some point in its
illustrious history, it was laying on its back, and a Wild Cherry
Pepsi got dumped onto it. Supposedly the speaker is fine, but the
soda seeped into the front panel of the amp, into all the pots and the
eq sliders, and most likely down onto the circuit board.

The good news is, it still works, it just sounds like shit. They say
it's kinda distorted, makes noises, and the volume fluctuates
constantly while you're playing. It can go from normal, to whisper,
to OMFGTHEWALLSARECRACKINGLOUD (in true Fender style) on whatever whim
it wants. Sounds like dirty/gummy pots to me. I fixed this on my old
Peavey Pacer many years ago with a $10 can of Contact Cleaner/
Lubricant from Radio Shack. (No soda in that case, just age and
dirt).

The other good news is that shortly after this happened, the guy and
his brother took it all apart and tried cleaning it up with Isoprophyl
Rubbing Alcohol. Hopefully this means that it hasn't had a lot of
soda on the circuit board for the last few years. However, something
tells me that the water content and lack of lubricant could seize the
pots.

I still have most of a can of that Contact Lubricant, and I'll happily
buy more if necessary. It'll probably work on the pots and sliders if
I treat them several times. If not, I could always replace them all.
Do you think it will also do any good (or harm) on the rest of the
circuit board? At this point, I almost wonder if gently agitating the
board in warm distilled water for awhile would do any harm, and/or
maybe some good.


I don't have it here yet, so I haven't taken it out to look at it.
It's very possible that the whole thing is a wreck, and if that's the
case I at least have a cabinet and (hopefully) a good speaker. I
might pick it up this weekend so I'll take a look then.

Thoughts?
 
Hey y'all. Been awhile since I've been here. I've missed the joint.

I might be picking up an old SS Fender bass amp from a guy at work for
dirt cheap. Like buy him a case of beer and it's mine, cheap.

Anyways, I don't know the details, but at some point in its
illustrious history, it was laying on its back, and a Wild Cherry
Pepsi got dumped onto it. Supposedly the speaker is fine, but the
soda seeped into the front panel of the amp, into all the pots and the
eq sliders, and most likely down onto the circuit board.

The good news is, it still works, it just sounds like shit. They say
it's kinda distorted, makes noises, and the volume fluctuates
constantly while you're playing. It can go from normal, to whisper,
to OMFGTHEWALLSARECRACKINGLOUD (in true Fender style) on whatever whim
it wants. Sounds like dirty/gummy pots to me. I fixed this on my old
Peavey Pacer many years ago with a $10 can of Contact Cleaner/
Lubricant from Radio Shack. (No soda in that case, just age and
dirt).

The other good news is that shortly after this happened, the guy and
his brother took it all apart and tried cleaning it up with Isoprophyl
Rubbing Alcohol. Hopefully this means that it hasn't had a lot of
soda on the circuit board for the last few years. However, something
tells me that the water content and lack of lubricant could seize the
pots.

I still have most of a can of that Contact Lubricant, and I'll happily
buy more if necessary. It'll probably work on the pots and sliders if
I treat them several times. If not, I could always replace them all.
Do you think it will also do any good (or harm) on the rest of the
circuit board? At this point, I almost wonder if gently agitating the
board in warm distilled water for awhile would do any harm, and/or
maybe some good.

I don't have it here yet, so I haven't taken it out to look at it.
It's very possible that the whole thing is a wreck, and if that's the
case I at least have a cabinet and (hopefully) a good speaker. I
might pick it up this weekend so I'll take a look then.

Thoughts?

With dirty equipment I've found over the years that fancy alchohols
and degreasers are a waste of time and money. The most effective
cleaning method is to be brutal and use a mix of really, really hot
water and washing up liquid dispensed by a pressure sprayer (one of
those pump up things). Particularly bad patches attended to by use of
a paintbrush.
It's essential that a thorough rinse in clean hot water is given
afterwards (pressure sprayer again), followed by drying at a high
temperature (say 40degC) for as long a time as possible.
Dishwashers can be even easier if the parts will fit in.
 
L

Lionel

Jan 1, 1970
0
The good news is, it still works, it just sounds like shit. They say
it's kinda distorted, makes noises, and the volume fluctuates
constantly while you're playing. It can go from normal, to whisper,
to OMFGTHEWALLSARECRACKINGLOUD (in true Fender style) on whatever whim
it wants. Sounds like dirty/gummy pots to me. I fixed this on my old
Peavey Pacer many years ago with a $10 can of Contact Cleaner/
Lubricant from Radio Shack. (No soda in that case, just age and
dirt).

The other good news is that shortly after this happened, the guy and
his brother took it all apart and tried cleaning it up with Isoprophyl
Rubbing Alcohol.

That's a big plus. I've fixed lots of equipment that's suffered drink
spills (coffee, coke, wine, beer, etc), & the single biggest factor
that determines whether it survives is how fast the power is removed &
the gunk washed out.
Hopefully this means that it hasn't had a lot of
soda on the circuit board for the last few years. However, something
tells me that the water content and lack of lubricant could seize the
pots.

Yes, absolutely.
I still have most of a can of that Contact Lubricant, and I'll happily
buy more if necessary. It'll probably work on the pots and sliders if
I treat them several times. If not, I could always replace them all.
Do you think it will also do any good (or harm) on the rest of the
circuit board? At this point, I almost wonder if gently agitating the
board in warm distilled water for awhile would do any harm, and/or
maybe some good.

If you're careful, it's a good idea. After you wash the board, you
also need to wash in alcohol. The important thing is make sure that
it's 100% dried out (gently!) before you next apply power. I put
boards on a folded towel & sit them in a dry, warm (30-40c or so)
place for at least 3 days to make sure that all the crevices (like
under chips) are totally free of moisture. The alcohol helps a lot
with this.
I don't have it here yet, so I haven't taken it out to look at it.
It's very possible that the whole thing is a wreck, and if that's the
case I at least have a cabinet and (hopefully) a good speaker. I
might pick it up this weekend so I'll take a look then.

Thoughts?

Go ahead. But you may need to replace the pots anyway.
 
H

Homer J Simpson

Jan 1, 1970
0
I still have most of a can of that Contact Lubricant, and I'll happily
buy more if necessary. It'll probably work on the pots and sliders if
I treat them several times. If not, I could always replace them all.
Do you think it will also do any good (or harm) on the rest of the
circuit board? At this point, I almost wonder if gently agitating the
board in warm distilled water for awhile would do any harm, and/or
maybe some good.

Use clean water with baking soda dissolved in it. Rinse off and let dry for
a week.
 
P

Phil Allison

Jan 1, 1970
0
With dirty equipment I've found over the years that fancy alchohols
and degreasers are a waste of time and money. The most effective
cleaning method is to be brutal and use a mix of really, really hot
water and washing up liquid dispensed by a pressure sprayer (one of
those pump up things). Particularly bad patches attended to by use of
a paintbrush.
It's essential that a thorough rinse in clean hot water is given
afterwards (pressure sprayer again), followed by drying at a high
temperature (say 40degC) for as long a time as possible.



** That is the EXACT method I have been using with 100% success for many
years to clean PCBs and heatsink modules contaminated by drink spills or
just accumulated grime blown in by a fan.

Dishwashers can be even easier if the parts will fit in.


** Ain't got one of them.

Be neat to dump a whole power amp in one ....



........ Phil
 
M

MassiveProng

Jan 1, 1970
0
Hey y'all. Been awhile since I've been here. I've missed the joint.

I might be picking up an old SS Fender bass amp from a guy at work for
dirt cheap. Like buy him a case of beer and it's mine, cheap.

Anyways, I don't know the details, but at some point in its
illustrious history, it was laying on its back, and a Wild Cherry
Pepsi got dumped onto it. Supposedly the speaker is fine, but the
soda seeped into the front panel of the amp, into all the pots and the
eq sliders, and most likely down onto the circuit board.

The good news is, it still works, it just sounds like shit. They say
it's kinda distorted, makes noises, and the volume fluctuates
constantly while you're playing. It can go from normal, to whisper,
to OMFGTHEWALLSARECRACKINGLOUD (in true Fender style) on whatever whim
it wants. Sounds like dirty/gummy pots to me. I fixed this on my old
Peavey Pacer many years ago with a $10 can of Contact Cleaner/
Lubricant from Radio Shack. (No soda in that case, just age and
dirt).

The other good news is that shortly after this happened, the guy and
his brother took it all apart and tried cleaning it up with Isoprophyl
Rubbing Alcohol. Hopefully this means that it hasn't had a lot of
soda on the circuit board for the last few years. However, something
tells me that the water content and lack of lubricant could seize the
pots.

I still have most of a can of that Contact Lubricant, and I'll happily
buy more if necessary. It'll probably work on the pots and sliders if
I treat them several times. If not, I could always replace them all.
Do you think it will also do any good (or harm) on the rest of the
circuit board? At this point, I almost wonder if gently agitating the
board in warm distilled water for awhile would do any harm, and/or
maybe some good.


I don't have it here yet, so I haven't taken it out to look at it.
It's very possible that the whole thing is a wreck, and if that's the
case I at least have a cabinet and (hopefully) a good speaker. I
might pick it up this weekend so I'll take a look then.

Microwave some 99% IPA up and give it a good hot alcohol bath.

Not assembled. Break it down into subassemblies, like the panel,
etc.

Being hot, the IPS should dislodge the soda remnants and surupy
slurry.

Then a good bake out in a 60C oven (140F). THEN, add the contact
spray, which might have some dry lube in it for the pot shafts.

Otherwise, replacing the pots that are sluggish to turn would be a
good step.

If you hot dip the PCB assy., keep from dipping any transformers or
inductors as the tapes used will have their adhesive backings
released, and the bake step above needs to be about a half hour, for a
PCB where you did get a transformer "wet", it would need an hour bake.
 
J

JeffM

Jan 1, 1970
0
That's going to make it fun.
From further down in the thread:
Phil Allison wrote:
#Be neat to dump a whole power amp in [a dishwasher]
#
Seems like that's what it might take
--if cleaning would work on all the bits.
I'd brace myself for the probability
that the panel-mounted parts will have to be replaced.
[email protected] jjdesigns.fsnet.co.uk said:
The most effective cleaning method is to be brutal
and use a mix of really, really hot water and washing up liquid
dispensed by a pressure sprayer (one of those pump up things).
I agree with everything you have said
....except one detail:
Particularly bad patches attended to by use of a paintbrush.
A paintbrush has soft bristles. An *acid* brush
http://www.solobrushes.com/pictures/pseries_lg.jpg
with the business end trimmed short for even more stiffness
is the tool.
Any place that sells industrial supplies (pastes) has them.
 
R

Rich Grise

Jan 1, 1970
0
Hey y'all. Been awhile since I've been here. I've missed the joint.

I might be picking up an old SS Fender bass amp from a guy at work for
dirt cheap. Like buy him a case of beer and it's mine, cheap.

Anyways, I don't know the details, but at some point in its
illustrious history, it was laying on its back, and a Wild Cherry
Pepsi got dumped onto it. Supposedly the speaker is fine, but the
soda seeped into the front panel of the amp, into all the pots and the
eq sliders, and most likely down onto the circuit board.

Wash it with carbonated water (club soda). That will get the water-
soluble sugars off of it, which is what gums things up. The contact
cleaner things are usually non-polar solvents, and sugar will just
shrug that off. And blow it dry, don't bake it dry - baking leaves
crud behind. With dry clean compressed air, the liquid water gets
blown away and takes the crud with it.

I used to fix video games and pinballs that were located in bars -
it's amazing what kinds of crud can get on boards in that kind of
venue.

Of course, it's nothing like cleaning medical devices that have been
dropped in a bedpan. =:-O

Good luck!
Rich
 
M

MassiveProng

Jan 1, 1970
0
Wash it with carbonated water (club soda). That will get the water-
soluble sugars off of it, which is what gums things up. The contact
cleaner things are usually non-polar solvents, and sugar will just
shrug that off. And blow it dry, don't bake it dry - baking leaves
crud behind. With dry clean compressed air, the liquid water gets
blown away and takes the crud with it.


Blowing on it does remove any (most) solids as the water/solvent gets
pushed off, but baking is STILL required. Especially for a water
/"club soda" wash, as PCBs are hygroscopic.

Get a clue, grisetard.
 
M

MassiveProng

Jan 1, 1970
0
I used to fix video games and pinballs that were located in bars -
it's amazing what kinds of crud can get on boards in that kind of
venue.

Funny, since the "boards" on a pinball are in the cabinet behind the
backglass.
Of course, it's nothing like cleaning medical devices that have been
dropped in a bedpan. =:-O

Funny, since practically all "medical devices" are immersible.
 
L

Lionel

Jan 1, 1970
0
Funny, since the "boards" on a pinball are in the cabinet behind the
backglass.

Lots of pinball machines have huge PCBs (& usually the PSU as well)
directly under the playing field.
Funny, since practically all "medical devices" are immersible.

Lots of them are, but not "practically all".
 
R

Rich Grise

Jan 1, 1970
0
Lots of pinball machines have huge PCBs (& usually the PSU as well)
directly under the playing field.

Well, actually, I've seen EM (electromechanical) pins that have
point-to-point circuitry right on the bottom of the case, under
the playfield, but the PCB ones usually put the PCB behind the
backglass.

The problem is a lot more prevalent with stand-up and cocktail
videos - but in either case, you'd be surprised where people can
spill their drinks!
Lots of them are, but not "practically all".

Big Dork simply has no clue - he's best left ignored.

Cheers!
Rich
 
M

MassiveProng

Jan 1, 1970
0
Well, actually, I've seen EM (electromechanical) pins that have
point-to-point circuitry right on the bottom of the case, under
the playfield, but the PCB ones usually put the PCB behind the
backglass.

The problem is a lot more prevalent with stand-up and cocktail
videos - but in either case, you'd be surprised where people can
spill their drinks!


Big Dork simply has no clue - he's best left ignored.


So are you, asswipe. Upright video games and cocktail versions of
upright video games are NOT pinballs, you retarded ****.
 
L

Lionel

Jan 1, 1970
0
Well, actually, I've seen EM (electromechanical) pins that have
point-to-point circuitry right on the bottom of the case, under
the playfield,

Yes, I've seen those too, although it's been quite a few years.
but the PCB ones usually put the PCB behind the
backglass.

Nearly all the ones I've seen have PCBs behnd the backglass, & under
the playing field.
The problem is a lot more prevalent with stand-up and cocktail
videos - but in either case, you'd be surprised where people can
spill their drinks!

I worked at an arcade for a while as a teenager, & nothing like that
would surprise me. ;^)
 
P

phaeton

Jan 1, 1970
0
Well, I got it home. The preamp and power amp are two different
boards connected by ribbon cable. Strangely, all the soda is on the
power amp board in the back. Further investigation reveals that the
amp was not 'on' at the time of the spill. It has been turned on
since the initial cleaning, and that's how they know it sounds like
crap. I haven't turned it on to try it out.

Lots of gunk everywhere, bridging traces and leads, but nothing looks
burnt and black or anything.

In lieu of a pump-up pressure sprayer, would a DIY car wash gun work?
Most of them have a 'low pressure jet' that's on by default, until you
squeeze the trigger (for high pressure). How about if I saran wrap up
the transformer and pots and hit it with the low pressure only, then
rinse well, and let it sit up in a sunny place for a couple of weeks
to dry out?

The sliders and knobs were really sticky and stiff, and I went ahead
and blasted them with the Contact Cleaner. All but one slider
improved in 'feel'. I'm going to let them sit a day or so, blast
again, and then track them with an ohmmeter to see if they follow the
curve like they should. If they don't, I won't be heartbroken.

Thanks for the help and suggestions thusfar.

-phaeton
 
J

John Popelish

Jan 1, 1970
0
phaeton said:
Well, I got it home. The preamp and power amp are two different
boards connected by ribbon cable. Strangely, all the soda is on the
power amp board in the back. Further investigation reveals that the
amp was not 'on' at the time of the spill. It has been turned on
since the initial cleaning, and that's how they know it sounds like
crap. I haven't turned it on to try it out.

Lots of gunk everywhere, bridging traces and leads, but nothing looks
burnt and black or anything.

In lieu of a pump-up pressure sprayer, would a DIY car wash gun work?
Most of them have a 'low pressure jet' that's on by default, until you
squeeze the trigger (for high pressure). How about if I saran wrap up
the transformer and pots and hit it with the low pressure only, then
rinse well, and let it sit up in a sunny place for a couple of weeks
to dry out?

The sliders and knobs were really sticky and stiff, and I went ahead
and blasted them with the Contact Cleaner. All but one slider
improved in 'feel'. I'm going to let them sit a day or so, blast
again, and then track them with an ohmmeter to see if they follow the
curve like they should. If they don't, I won't be heartbroken.

Thanks for the help and suggestions thusfar.

It is not at all important that you blast the water in with
any force. All you need is its ability to dissolve the
sugars and slats left behind, and a simple stream will do
that. So you should be able to use a low pressure stream
and avoid dumping it through the transformer (unless it has
soda run through it). The contact cleaner you have used
will make it harder for the water to wet the surfaces
originally contaminated, so you may have to start with a
flow of water mixed with dish washing detergent to get under
the oils in the contact cleaner.

When everything looks clean and just wet, a thorough drying
is all that you should need to test the unit. Then, if the
pots are noisy, a little contact cleaner might help
lubricate them.
 
L

Lord Garth

Jan 1, 1970
0
John Popelish said:
phaeton wrote:
It is not at all important that you blast the water in with
any force. All you need is its ability to dissolve the
sugars and slats left behind, and a simple stream will do
that. So you should be able to use a low pressure stream
and avoid dumping it through the transformer (unless it has
soda run through it). The contact cleaner you have used
will make it harder for the water to wet the surfaces
originally contaminated, so you may have to start with a
flow of water mixed with dish washing detergent to get under
the oils in the contact cleaner.

When everything looks clean and just wet, a thorough drying
is all that you should need to test the unit. Then, if the
pots are noisy, a little contact cleaner might help
lubricate them.

Don't use tap water or mineral laden drinking water. Use
distilled water. If there is no plastic in the way, I chase the
water with methyl alcohol then blow it dry.
 
Don't use tap water or mineral laden drinking water. Use
distilled water. If there is no plastic in the way, I chase the
water with methyl alcohol then blow it dry.

The great bulk of the wash can be done with warm tap water, even hard
water. Just the final rinse is best done with distilled water.
Before that, the contamination being washed off is dirtiuer than the
tap water. No sense rinsing gallons of distilled water down the
drain, brown with Coka Cola.
 
L

Lord Garth

Jan 1, 1970
0
Okay, that makes good sense. I had DI water available from a tap
so it was never an issue. I also used nitrogen to dry the parts, also
from a wall tap.
 
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