Single Dead Laptop Key: What Should the Technician Replace Next?
Short answer
A Replace the laptop keyboard assembly, because a dead key after debris removal means the membrane switch failed and there is no per-key switch to swap.
Question
Key Takeaways
It tests whether you understand that laptop keyboards are sealed, non-modular assemblies, so the trap is reaching for the cheapest part (a keycap) instead of the cheapest repair that actually restores an electrical keystroke.
A laptop key that stops registering after debris has been ruled out points to a failed dome/membrane contact under that key, which is why the entire keyboard module — not a keycap or a bare switch — is the cost-effective replacement. This page explains the 220-1201 reasoning behind replacing the laptop keyboard and why the cheaper-looking part swaps fail.
Common mistake: Picking the keycap (D) because it is the least expensive part — a fresh keycap cannot fix a key whose membrane contact no longer closes the circuit, so the fault returns the moment the laptop boots.
Expert Analysis
Why the Answer Is Correct
On virtually every laptop, the keyboard is a sealed membrane assembly: the scissor mechanism and rubber dome sit on a printed membrane sheet that cannot be serviced key-by-key. Once the technician has cleared debris and the single key still does not register, the failure is electrical at that dome contact, and no vendor sells that contact as a standalone field-replaceable unit. Replacing the whole keyboard module (A) is therefore the cost-effective repair in the A+ sense — the least expensive action that actually restores the keystroke, typically a sub-$30 part held in by a few screws or clips. Objective 1.1 expects you to know which mobile components are field-replaceable and which are replaced as a unit, and laptop keyboards fall firmly in the second group.
Why the Other Options Are Wrong
Replacing the key switch (B) assumes a socketed mechanical keyboard where each switch can be pulled and re-seated; laptop scissor mechanisms have no such switch, so this would mean micro-soldering onto a membrane, which is not a bench-level repair. Replacing the circuit board (C) is either the same job as replacing the keyboard at a higher cost, or — if read as the system board — wildly out of scope for one dead key. Replacing the keycap (D) addresses only cosmetic or mechanical cap damage such as a missing, cracked, or misaligned cap; it does nothing when the key physically depresses but produces no character. On a laptop, a keycap is a cover, not a switch.
Community Comment Notes
Several learners picked the keycap on pure price logic — Elle framed the goal as being "cost-effective and targeted" and suggested removing the cap to inspect the mechanism, while acf9805 argued to "try the smallest and cheapest fix first." That reasoning stops working the moment debris is excluded, because the remaining fault is electrical rather than mechanical. user=351199f pushed for the switch, arguing it is "the mechanical sensor underneath the key," which is true of desktop mechanical boards but not of a laptop membrane. dddba0a's practical objection — "Who is going to Solder and disassemble a keyboard" — is exactly the doctrine being tested: you replace the module, not the switch.
Answer: A
Official Reference
https://www.comptia.org/certifications/a
This link opens the official vendor documentation in a new tab.
Exam Strategy
When a stem says "cost-effectively," translate it as the cheapest action that actually fixes the fault, not the cheapest part on the list. On mobile hardware items, first ask whether the component is field-replaceable as a unit (laptop keyboard, battery, display assembly) or truly modular — that single check eliminates the per-key answers.
Frequently Asked Questions
Why can't a technician just replace the key switch on a laptop keyboard?
When would replacing the keycap (D) actually be the right call?
Discussion 5 contributions
Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.
From public community threads 5
-
351199f 👍 2 Answered BB. Replace the key switch. Despite replacing the keycap being the cheapest option here, it wouldn't actually do anything to fix the keyboard. Its key switch is the mechanical sensor underneath the key that actually detects when the key is being pressed down, therefore the problem likely falls with it. You can buy like a 100 on these things for 20 bucks (depending on the quality your want) making them the cheapest option.
-
Elle 👍 2 Answered DD. The key phrase here is to be cost-effective and targeted in the fix. The tech already checked for debris so the next best low cost step is to remove the key cap and inspect the mechanism underneath. Sometimes the key cap is just loose it could be misaligned even sticky so receding it or swapping it will help resolve the issue.
-
dddba0a 👍 1 Answered DWho is going to Solder and disassemble a keyboard, just replace the cap or get a new key cap
-
acf9805 👍 1 Answered D52. D — Replace the keycap 🧸 One key is broken, so try the smallest and cheapest fix first.
-
ishan94 👍 1 Answered DReplacing the keycap is the simplest and least expensive option
Reader comments & corrections
No reader corrections yet — spotted an error or have a note? Share it below.
Related Analysis
Practice All 220-1201 Questions
Access 105 questions with complete answers and detailed explanations.
View Full 220-1201 Practice Test →