TECH GURU's out there, how to clean Circuit Board?

Timrhu...Contact cleaner is for contacts! Some electronic parts will not take kindly to such treatment. (Don't ask how I know). I know Freon is safe, but you can't get it. I know that a safe Freon replacement cleaning fluid exists, and I wish I could give you the name of the stuff. Do some research.

>> 03-09-06: Rapogee
>> Thank you very much guys, very helpful.
>> Just to clarify, I tried the micro vacum and compressed
>> air and that did not work. There is hair and dirt still
>> sticking,

Rapogee, thanks for the feedback! I didn't think that compressed air would work on the greasy grime.

The MG Chemicals Flux Remover looks very much like the Chemtronix stuff that I recommended. FYI: the Chemtronix stuff is an industrial product that is used in my engineering lab here where we populate PCBs to test out some of our ICs that go into cellphones. My recommendation was *not* a butt-pull - we use this stuff nearly daily to get guey stuff off our PCBs esp things like flux paste/fluid. Like the pix on MG Chemicals webpage, the Chemtronix can comes w/ that red colour straw nozzle that allows us to point the fluid more-or-less exactly where the guey stuff is. We have *not* ruined any PCBs so far & we have been in operation for over 10 years!

I was thinking of this last eveing & here is another idea: how about using "Goo-Gone"? I have used it to remove several sticky things (like stickers on CD jewel cases, airport security stickers on suitcases) but never on a PCB so far. This Goo-Gone is citrus-based (atleast the one that I have) & it does a great job of removing guey stuff. I've used some alcohol post Goo-Gone to get do the final clean-up. In your case, use a hair-dryer to dry the PCB thoroughly + let it air dry for 24 hrs before turning on the amp.
IMHO, this should really do the job for you. FWIW.

Eldartford, I used the name contact cleaner as a generic name, my mistake. I brought the can in and here is the info. The brand is Chemsearch, the can says Lexite PS, Electrical Cleaner Dergreaser, the label states "safe on plastic, rubber and plastic - no residue - no disassembly required." I have used this on circuit boards repeatedly to remove residue from spills, leaky caps and rodent urine and fecal matter (disgusting). This stuff works pretty well without harming boards. Given time it may cause some deterioration but I haven't noticed it. The residue is probably more harmful than the chemical.
Now I recommend first cleaning the affected area with denatured alcohol and a brush and then spraying the cleaner. That's how I do it. Good luck.

Thank you everyone, Bombaywalla and all of you out there!
Very knowledgeble people and this is why I like forums such as these, very educational and helpful.

I used all your advise, paid $10 for the unlta wash from Radio Shack, $4 for brushes from the dollar store, cut the brshes up to enhance the stiffness and control .5 inch sprayed over the brush and cleaned process, never sprayed directly to the board only on some empty areas than needed.
Used a little alcohol or some areas with cotton swab and too my time and cleaned it up good. WORKED!
Images enclosed:

Believe me the board was originally brown in colour with dirt all over.... like the lable shown with the serial board #####, NOW ITS GREEN as original... Thank you very much. First 2 images shows cleaned board, last shows the cleaner I used, I also used rubbing alcohol or certain stuborn areas very little and with caution.

http://img.photobucket.com/albums/v430/rainbowrav/closer2.jpg

http://img.photobucket.com/albums/v430/rainbowrav/closer.jpg

http://img.photobucket.com/albums/v430/rainbowrav/worked.jpg

Looks good as new in pics. Kudos on a job well done!