For safe computer maintenance, which product should be used to clean smudged keys on a keyboard without harming plastics or leaving residue?

Introduction / Context:
Keyboard cleaning must remove oils, smudges, and grime while avoiding damage to plastic keycaps, printed legends, and internal switch mechanisms. The right cleaner should evaporate quickly and leave minimal residue to prevent sticky keys or long-term deterioration.

Given Data / Assumptions:

• Objective is surface cleaning of keycaps, not internal switch repair.
• Materials include ABS or PBT plastics and printed or UV-coated legends.
• We want a commonly available cleaner that is safe for electronics maintenance.

Concept / Approach:
Denatured alcohol (and, in practice, isopropyl alcohol 70–99%) is widely used because it evaporates quickly, dissolves skin oils, and typically does not attack most keyboard plastics when used sparingly on a lint-free cloth. Products with oils (e.g., silicone) or surfactants (many all-purpose cleaners) can leave residues that attract dust or seep into switches.

Step-by-Step Solution:

Verification / Alternative check:
Electronics service practices recommend alcohol-based cleaners for plastics and housings. After cleaning, keys should feel dry and non-greasy within minutes, indicating minimal residue.

Why Other Options Are Wrong:

• TMC solvent: Unclear formulation; may be too aggressive for consumer plastics.
• Silicone spray: Leaves oily film that traps dust and can migrate into switches.
• All-purpose cleaner: Often contains surfactants and fragrances that leave residue.
• None of the above: Incorrect because denatured alcohol is appropriate when used correctly.

Common Pitfalls:
Spraying liquid directly on the keyboard, using excessive force on printed legends, and confusing alcohol content (use moderate strength and avoid acetone or harsh solvents).

Final Answer:
Denatured alcohol