The answer is motherboard voltage incompatibility, because DDR3L modules operate at 1.35V while standard DDR3 requires 1.5V, and many older motherboards lack the circuitry or BIOS support to supply or regulate the lower voltage. When a technician installs DDR3L into a board designed only for standard DDR3, the system may fail to boot or become unstable since the memory controller cannot properly negotiate the reduced voltage. On the CompTIA A+ Core 1 220-1201 exam, this question tests your understanding of RAM voltage standards and physical compatibility—a common trap is assuming DDR3L is backward-compatible in all DDR3 slots, but it is not. Remember the memory tip: “1.35V is low, but not every board will go.” Always check the motherboard’s QVL or manual before mixing voltage tiers.
220-1101 RAM Practice Question
This 220-1201 practice question tests your understanding of ram. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A technician is tasked with upgrading a workstation that uses DDR3 RAM. The technician purchases DDR3L modules (low voltage) and installs them. The system fails to boot. What is the most likely reason?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The motherboard does not support the lower voltage of DDR3L.
DDR3L modules operate at 1.35V, while standard DDR3 operates at 1.5V. Many older motherboards do not support DDR3L, or they require specific BIOS settings to handle the lower voltage. The technician should verify motherboard compatibility before installation.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
The DDR3L modules are physically incompatible with DDR3 slots.
Why it's wrong here
DDR3L and DDR3 have the same notch position and pin count, so they are physically compatible.
✓
The motherboard does not support the lower voltage of DDR3L.
Why this is correct
Some older motherboards cannot supply or regulate 1.35V, causing boot failure.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Static NAT maps one inside address to one outside address.
✗
The technician installed the modules in the wrong slots.
Why it's wrong here
Wrong slots would typically cause no boot or single-channel operation, but not specifically due to voltage.
✗
The DDR3L modules are defective.
Why it's wrong here
While possible, the most likely cause given the scenario is voltage incompatibility, not defect.
Common exam traps
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Trap categories for this question
Scenario analysis trap
While possible, the most likely cause given the scenario is voltage incompatibility, not defect.
Detailed technical explanation
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
Static NAT maps one inside address to one outside address.
PAT allows many inside hosts to share one public address using ports.
Inside local and inside global describe the private and translated addresses.
NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
→Identify inside and outside interfaces first.
→Check whether the scenario needs static NAT, dynamic NAT or PAT.
→Do not confuse NAT matching ACLs with normal packet-filtering intent.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Real-world example
How this comes up in practice
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this 220-1201 question in full detail.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related 220-1201 NAT questions on configuration and troubleshooting.
RAM — This question tests RAM — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: The motherboard does not support the lower voltage of DDR3L. — DDR3L modules operate at 1.35V, while standard DDR3 operates at 1.5V. Many older motherboards do not support DDR3L, or they require specific BIOS settings to handle the lower voltage. The technician should verify motherboard compatibility before installation.
What should I do if I get this 220-1201 question wrong?
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related 220-1201 NAT questions on configuration and troubleshooting.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Static NAT maps one inside address to one outside address.
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