How To Clean An Old Stereo Receiver

Simply picked up a Marantz 2235b and the innards appear to be coated with a fine oil mist and subsequent low-cal layer of dust.
All the others just needed air and de-oxit.

This needs a little more aggressive cleaning. Not bad but the contaminants may be somewhat conductive so I want them off the boards.

Contact cleaner? Booze? Restriction cleaner (tetrachloroethylene)? What is recommended that will make clean but not harm the boards and components? Brand names or generic chemical name OK

I know non to use not-chlorinated restriction cleaner, since it'due south virtually 50% acetone.

Thanks

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c.coyle Fighting the Dunning-Kruger issue. Subscriber

I used citrus degreaser on an amp that was smothered in cigarette goo. Worked nicely, only a piffling residue, which I removed with Simple Green. Home Depot and Lowes carry various brands..
Be wary of the tuning lath and tuning cap. (the thing with the blades?) practise not broadcast whatsoever sprays as it just makes the cleanup more pita. I use Q-tips and "mop" up effectually the components. Discharge caps or make sure they are discharged!! common rubbing alcohol volition kill off fume or smells on the metal casing. Make sure what you lot utilize doesn't accept off any on board pcb silk screen markings. do non use annihilation but a common mix of dish lather for the confront plate!
No on the brake cleaner - pretty potent stuff and I am not aware of anyone here who has used it on PCB's and components. Unknown territory, at least to me. I wouldn't use information technology.
No on the contact cleaner. Contact cleaners should be used inside switches or applied directly to metallic contact areas like connectors, fuse holders, etc. Not simply sprayed like a blanket. Some contact cleaners leave residue that will take hold of dust. But even if it leaves no residue, cleaning general grunge from lath and the surfaces of components is not what it is made for.

I similar 91% isopropyl alcohol. Bachelor in any pharmacy or the pharmacy department of the large concatenation stores. Exist aware that some products called "rubbing alcohol", which will be on the shop shelf right next to the plain alcohol, could have boosted ingredients that you wouldn't want.

Merely patently 91% ISO. It is inexpensive and can be used generously with small artists brushes, Q-tips, etc. On a really muddied unit, I like to set the unit on its side (terminate) with some paper towels underneath, then slop the alcohol on heavily (with maybe a 1" pigment brush) from the highest point, so that it runs down through the components on the board and is caught by the paper towels at the bottom. While the lath is wet, a smaller artists brush can exist used in tight or especially dirty areas. Be gentle when working with any type of tools effectually delicate components. Also, I would be careful not to allow the alcohol to impact any exterior wood panels.

Every bit Binkman noted, brand sure that caps are discharged. If you don't know how to discharge the main filter caps, I would suggest leaving the unit unplugged for a couple days before working inside it. Nearly units would discharge quicker than that, merely some may not.

Last edited: Apr 14, 2016
I add some pure acetone to alcohol, stops that stickiness when information technology dries, y'all can go it from beauty suppliers, don't employ boom polish remover it contains a host of other stuff.

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You would be surprised at the excursion boards I've cleaned up. Well-nigh electric components don't care about getting moisture. Use your head, don't rinse a transformer in the kitchen sink. And if a transformer does get wet, bake it in the oven at depression heat for a few hours.
I accept pulled PCB'due south out of industrial controls (CNC milling machines) that were and so covered in dirt that yous couldn't make out the components on the board, a thick layer of dust and dried coolant roofing everything, the legs on IC's not even visible.
Spray them with some Simple Green and using a soft castor gently scrub them down, rinsing and respraying as needed. When they are clean, I drain them on edge and find a warm spot to let them dry for a few hours.
They turn out looking factory fresh and most times the problem that I came in to fix is gone, the machine works fine.
Often times there are small trimmer pots, I used to be nervous near them just as long equally the lath gets actually dried, it doesn't seem to hurt them.
I've never done a chassis with betoken to point wiring merely if I had a grungy one to clean up, I'd give it the aforementioned treatment. A nice baking in the oven after cleaning at virtually 125F to 140F for a few hours would ensure that it dry's well.
Most industrial control repair shops take large cleaning tanks that they dunk complete chassis in, removing transformers start. It'southward accepted practice.
BillWojo
Windex has as well been used with proficient results. Years agone there was a guy on AK that put his stuff in the dishwasher. He would remove anything that would have an issue with water and then in information technology went. The pics he posted looked pretty clean.
Well I experimented for u.s. all.
Real chlorinated restriction cleaner (trichloroethylene and CO2) worked fine and did non damage any markings on caps, PCBs, chassis, etc.

Blow with air, make clean and flush with trichloroethylene, blow with sir, let dry and clean and lube pots and switches. Re-assemble. Works well and looks adept with all new lights

I would exist afraid to try acetone. Information technology's one of the about aggressive solvents I know. Laquer thinner being right there with it. (acetone + other stuff like MEK, etc.).I work in heavy industry, then I know where you're coming from.
This wasn't bad enough to warrant getting information technology wet with water, or dunking it in the parts washer. Simply a light oil film and some household grit (no nicotine).

Y'all should see the looks I get from my wife when she finds something I've been "baking" in the over...(baked "crinkle" paint is near indestructible on Harley parts).
I picked up a pack of these at local northern tool (no amalgamation.) These are not cotton twisted ear swabs only an excellent deal. You lot'll notice many uses and your better half may raid your stash for cosmetics, too.
http://www.northerntool.com/shop/tools/NTESearch?storeId=6970&ipp=24&Ntt=swabs

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I used the hose in one case, but I tin't think what it was I was cleaning. I will often become things wet that many others would not, just even I was nervous that time.
Cool stuff.
I'k a shooter, and gear caput, so I'g always looking for stuff like this.

Wonder if Fastenal carries these? No Northern Tool around here, except on line...
People on the arcade forums are known to clean PCB's and fifty-fifty monitors with water and diverse things. Elementary Green is a popular choice. I've cleaned an Atari 2600 lath in the dishwasher (no soap), I've done PCB'south in the sink with dawn, and I've taken a CRT monitor apart, doused it with elementary green and low pressure washed out the entire affair (chassis, board, tube) and none of them have been any worse for the article of clothing. The key is making sure they are completely dry before putting whatsoever power back to them.
RossW AK Subscriber Subscriber

I ran a whole AU-717 (minus ability transformers) through the dishwasher once. Left information technology out in the lord's day for a whole day to dry and all was well.

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Ross6860; I believe they link west. no. tool has online ordering. won't postal service links only looks similar they will send or email them. I liked the pack considering it had over 300 pieces. comes in a resealable type tag handbag, air tight. Hey if using water solutions, just let dry and reuse.
I have tried brake cleaner. Don't exercise it.
I ruined the paint on the dial of one receiver.
I too noted that when I used it on a Q-tip to make clean upwardly around components on a PCB that the surface felt sticky long afterward. And then the finish on the top surface of the board was at least partly soluble.
Information technology likewise removed pigment markings from capacitors.
I moved the tin to a different storage location because looks to much similar the can of CRC contact cleaner.
I used a $two tin can of carpet spot remover to clean up a cigarette smoke covered receiver, using a Q-tip, wetted in information technology, to scrub the boards around components.
It worked really well, dried fast, and did no harm.
Blueish Magic brand from Dollar General.
Brake Cleaner is NOT Brake Cleaner, is not brake cleaner. In that location are many unlike components and solvents out there under the generic "brake cleaner" moniker. One needs to read the label and know what's in at that place.
The one I apply is trichloroethylene and CO2. No stickiness, no blurring or whatever markings on the lath, caps or components. No paint damage, either

Now brake cleaner with whatsoever acetone, I wouldn't even try. Acetone is a major component in lacquer thinner and will cut just about any paint or ink, and assault plastics (that stickiness is the plastic dissolving).

Equally some have stated, both Simple Green and Super Clean have permanent places in my garage. Simple Green is my #1 "go to" cleaner that I've never seen injure anything. Super Clean sometimes leaves a cloudy residue a little harder to rinse than Elementary Green.

Nosotros apply Super Clean to water wash gas turbines at work (the inside of the turbine, by and large the compressor/gas producer, not so much the ability wheels). I'll bet they never though that it would be used for that...
@Ross6860 - It is good that you lot were non able to see any visual bear witness of impairment past using restriction cleaner on the PCBs in your amp.
But, polystyrene caps are sensitive to solvents (then says one of our wisest ones). Those types of caps are also known to exist sensitive to soldering estrus. They are just plain fragile. Absence of visible damage to lettering on other components, does not preclude the possibility of other types of damage that may be more than subtle, difficult to notice, or possibly have time to develop.

Something else that I would consider is that anything sprayed liberally onto an amp PCB is likely to cease up inside of open up trim pots. When it dries it could potentially leave backside some rest that could potentially bear on electrical conductivity. Inside of regular pots...aforementioned possibility.

I acknowledge that is a lot of "ifs". But why run a risk using a relatively unknown method? IMO, i should always starting time with the gentlest method and only increment intensity if necessary. And personally, I would prefer using methods that are known to, and that accept been discussed many times by, the AK community.

I guess I am posting this for others every bit you have already cleaned your boards. I hope that all is well with your 2235b, both now and for many years to come.

Last edited: Apr 17, 2016

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DEOXIT D-v
I can't imagine.....
jheu02 AK Subscriber Subscriber

Before

Cleaning with Simple green solution

Baking

Subsequently
For those afraid of acetone, I have been using a "mixture" of alcohol and acetone 50/50 to be precise for years and never had a problem with it removing whatever marking or melting anything even when I scrub information technology with an old toothbrush (my wife always complains when I utilize her new one), it dries quickly without stickiness. That existence said I am going to become some simple green and effort that as well.