Single Dead Laptop Key: What Should the Technician Replace Next?
A help desk technician inspects a laptop keyboard because a single key has stopped working. The technician checks the keyboard for debris. Which of the following actions should the technician do next to troubleshoot the issue cost-effectively?
Community Insight
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.
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.
Community Discussion (5 comments)
Comments & Corrections
No comments yet — spotted an error or have a note? Share it below.
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
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?
Laptop keys use a scissor mechanism over a rubber dome bonded to a membrane sheet, so there is no socketed switch. Swapping one means desoldering the membrane, which costs more than a new keyboard module.
When would replacing the keycap (D) actually be the right call?
Only when the cap itself is missing, cracked, or misaligned but the key still registers when pressed. Here the key has stopped working entirely, so the cap is not the fault.
Related Analysis
Practice All 220-1201 Questions
Access 105 questions with complete answers and detailed explanations.
View Full 220-1201 Practice Test →