How do I clean my computer using isopropyl alcohol?

If you're using high purity isopropyl alcohol, the advantages are that it is non conductive (being a non polar solvent), is not terribly reactive with the things you'd normally find in a computer, and generally dries fast. Water is a polar solvent, so you don't want to be using it in computers in larger quantities. 70% seems to be what people use, but you really want to be using 90% or better.

It's a very effective cleaner that at the quantities you use won't end up poisoning you, or dissolving your fingertips.

It's apparently safe to immerse entire devices in isopropyl alcohol—it seems to be a common way to save 'dead' cellphones—but I wouldn't recommend it as you'll see. It probably won't damage electronics; this thread on the HP calculator forums talks about immersing an entire calculator in alcohol, though with no follow up on whether it works.

via here - no idea on the original source.

And this is allegedly an entire PC soaked in rubbing alcohol. (No, do not do this. isopropy alcohol is highly inflammable - it will evaporate into something that can be ignited at low temperature (13-15 degrees), and will catch fire at around 400 degrees C, and we do not want to be responsible for house fires. BAD BAD IDEA.) And since this is kinda being mentioned in the comments (Its potentially explosive under the right conditions - I do not recommend trying to blow up plastic water jugs unless you're a trained professional and/or a chemistry teacher).

It will, however, probably dissolve things like thermal paste (which can be conductive, especially in formulas that contain metal.) As such, you don't want to be using it in bulk (by spraying or dipping a whole panel.) Additionally, it's a bad idea to combine it with grease, since you might end up dissolving some minor thing—conductive stuff in CPU sockets is bad, as would be accidentally removing all the lube from the mechanical parts of a drive. It'll also loosen any stickers present on the hardware. Apparently it also does nasty things to plexiglass and Lucite, so test before you clean any plastic bits.

Applying it to a paper towel may leave lint (coffee filters seem to be a common lint-free alternative), and the computer has lots of bits that stick out which may catch and rip out bits of it. I've generally used the stuff for spot cleaning on a cotton swab for particularly nasty, hard to remove dirt. It's also pretty good for cleaning contact pins or dirty lenses on optical drives (often using a lense cleaner) VERY carefully. As such, while alcohol itself might be safe, be very sure to clean the surfaces again after you have removed the intended residue with something lint free.

You'll also want to be careful with a cleaning cloth, tissue or other cleaning material not to bend anything. Bent pins are a PITA.

There are also large, pre-moistened wipes—there's variations for screens and other surfaces—that also contain other substances. These are excellent for external cleaning, and are lint free.

In most cases, air dusters for electronics and a dry microfiber cloth for surfaces work for me. Save the alcohol for tough situations like cleaning off heat sink compound or stuck-on dirt.

TL;DR: "How do I clean a computer with isopropyl alcohol?"

Sparingly. Use it when you need to clean electrical contacts and need to remove tough-to-remove substances. It's tricky for bulk cleaning but works well with specific issues. It's definitely the thing to use when cleaning monitors, degreasing a touch screen (ewww) or for cleaning dirty contacts. In many cases an air duster may be safer since you aren't touching the contacts.

Sources: wikipedia - for the chemistry bits.

It should be okay to clean all of your computer with isopropyl alchohol. The alchohol vaporises at room temperature, so just make sure it is completely dry before connecting the power again. I'd be carefull which paper towels you use, as some paper towels tend to leave behind small traces of paper.

I usually use a cotton but when cleaning my computers.

Two sources explain very well the subject :

• How to Clean Your PC, Inside and Out, section "Deep-Cleaning the PC"
• How to use ArctiClean Thermal Material Remover and Surface Purifier
  which is the Arctic Silver manual for using their ArctiClean product (substitute ArctiClean with isopropyl alcohol).

The boiled-down answers to your questions are :

Is is safe to use alcohol?

It can be used freely on the motherboard, fan and thermal paste, but not on the raw CPU, RAM, add-on cards, CMOS battery and of course disks.

What specific techniques should be applied?

If you strip-down from the motherboard all the above parts, you can even dunk it in a bath of 99 percent isopropyl alcohol.

Great precaution should be used for the CPU. The following extract is from Arctic Silver :

• If you are removing thermal material from a heatsink or waterblock that has already been mounted, detach the heatsink or waterblock from the CPU and remove the CPU from the motherboard. Place both on a clean, flat working area with the thermal surfaces facing up.

• Examine both thermal surfaces. Note whether the thermal interface material is a thermal pad (wax-based) or thermal compound (grease), then prepare the surface(s) as follows:

  • Pad - Use a credit card or similar plastic piece to scrape off the majority of the pad. Be careful not to scratch the base of the heatsink.

  • Compound - Use a dry cloth or paper towel to wipe away loose material.

• Fully saturate the remaining thermal pad or compound with several drops of ArctiClean 1 and wait 30 to 60 seconds for the thermal material to dissolve.

• Gently wipe with a cloth or paper towel to completely remove thermal material.

What are some concerns?

Do not use isopropyl alcohol for any other component than thermal paste, fans or the motherboard. Use alcohol gently applied to a cotton swab, paper towel or toothbrush - do not spray.

Use pure isopropyl alcohol or you risk leaving residues on the cleaned surface.

Some advice from Arctic Silver you might not think of :

Remove any rings or other jewelry that could scratch the surfaces being cleaned.
Coffee filters are excellent, inexpensive lint-free cloths.

Why should it, or shouldn't it be used?

It should be used for deep cleaning. For the occasional one use compressed air. Specialized materials, such as ArctiClean, might be better than pure isopropyl alcohol, but this hasn't been proved.

partial answer:

2) any parts which may have reaction with alcohol (high concentration) . some examples:

• your keyboard and any plastic case may de-color
• the insulation coating of motherboard, (some motherboard have used insulation spray to pass ESD test.
• some cheap plastic parts, some of china capacitors will actually melt and deform in alcohol.

• your warranty code, "make sure you won't wipe it to white so the warranty void"

  anyway, pull off the plug and let it dry will be fine.