- The Exam at a Glance
- Test-Day Rules and Delivery Options
- Domains 1-2: Safety, Assembly and Disassembly
- Domains 3-6: Boards, CPUs, Memory and Storage
- Domains 7-9: Adapters, Ports and Power
- Domains 10-11: Networking and Portables
- Domains 12-14: Troubleshooting, Operating Systems and Files
- Pathways, Rollover and Renewal
- Sequencing Your Review Around the 14 Domains
- Frequently Asked Questions
- The Computer Service Technician exam from ETA International is 80 questions in two hours, with a 75% passing score.
- Exam fee is USD 80; remote proctoring through ExamRoom.AI adds USD 16, even on a free retake.
- It is a proctored theory exam only; there is no hands-on assessment component.
- Fourteen unweighted competencies cover safety through file management, including Windows, Linux and Apple macOS.
The Exam at a Glance
This page is a one-page memory aid for the Computer Service Technician credential issued by ETA International. Everything here refers to that credential only. If you want the longer walkthrough, pair this sheet with the CST Study Guide and the full CST Exam Domains guide.
| Item | Must-Know Fact |
|---|---|
| Issuing body | ETA International |
| Format | Proctored theory examination, no hands-on assessment |
| Questions / time | 80 questions in two hours |
| Passing score | 75% |
| Exam fee | USD 80 |
| Retake | One free retake within one year of the initial session |
| Certification term | Four years |
| Content outline | 14 unweighted competency headings |
Because the 14 headings are unweighted, you cannot safely skip any of them. A common mistake is to over-invest in operating systems because they feel familiar while neglecting power concepts or safety. Every heading is fair game, so breadth beats depth. For the arithmetic behind the cut score, see CST Passing Score; at 75% on an 80-question exam, you need to answer roughly three out of every four questions correctly.
Test-Day Rules and Delivery Options
Where and how you test
Onsite testing is administered by an ETA Certification Administrator, using either Trapeza online testing or paper and pencil. Remote proctoring through ExamRoom.AI is also available, but it is arranged through ETA rather than booked independently, and it carries a USD 16 two-hour proctoring fee. That fee applies even when you are using your free retake, so budget for it twice if you test remotely both times. The full cost picture, including renewal, is covered in CST Certification Cost.
What to bring and what you may use
- Photo ID is required.
- Scratch paper is permitted, but used sheets must be surrendered at the end.
- A non-programmable scientific calculator is permitted. Practice with the kind of calculator you will actually carry in, since programmable models are not allowed.
The calculator allowance is a hint about content: expect some questions involving electrical relationships, conversions or capacity math. Know when to reach for the calculator and when a quick mental estimate is enough. For scheduling logistics, see CST Exam Dates.
Key Takeaway
Treat the free retake as insurance, not a plan. It is valid for one year from the initial session, but a remote retake still costs USD 16 for proctoring. Aim to pass the first time by gauging readiness with timed practice on the CST practice tests before you sit.
Domains 1-2: Safety, Assembly and Disassembly
Domain 1: Safety Procedures / Handling / Environmental Awareness
This is the foundation. Technicians are expected to protect themselves, the equipment and the environment.
- Electrostatic discharge (ESD) prevention: wrist straps, mats, proper handling of boards and modules
- Safe handling of components that hold charge or are sensitive to shock and static
- Awareness of proper disposal and environmental considerations for electronic equipment
- General workplace safety when opening powered or recently powered equipment
Domain 2: Computer Assembly and Disassembly
Know the logical order of building and taking apart a system, and why that order matters.
- Component installation sequence and orientation (keyed connectors, pin-one markers)
- Correct seating of processors, memory modules, drives and expansion cards
- Cable routing and connection of front-panel and power leads
- Verifying a clean first boot after assembly
Safety questions tend to reward the cautious answer. When two options both seem workable, the one that protects people and hardware first is usually correct.
Domains 3-6: Boards, CPUs, Memory and Storage
Domain 3: Motherboards / Mainboard and Buses / System Resources
The board ties everything together, so expect questions on how components communicate.
- Form factors, chipsets and expansion slot types
- Bus concepts and how data moves between components
- System resources such as IRQs, I/O addresses and DMA, and how conflicts arise
- BIOS/firmware setup basics and configuration options
Domain 4: Processor Characteristics
Know what distinguishes processors and how they relate to the board.
- Clock speed, cache, core concepts and socket compatibility
- Cooling requirements and thermal considerations
- Matching a processor to a compatible board and memory
Domain 5: Additional Memory Characteristics
Memory questions are about compatibility and behavior, not just capacity.
- Module types, speeds and form factors for desktops and portables
- Matching memory to what the board and processor support
- Symptoms of faulty or mismatched memory
Domain 6: Secondary Storage Devices
Know the devices, their interfaces and their failure modes.
- Hard drives, solid-state storage and optical media
- Interfaces, connectors and configuration
- Partitioning and formatting concepts at a hardware-service level
- Capacity, performance and reliability tradeoffs
ETA's competency document instructs candidates to retain the issuer's named legacy and current technologies. Do not assume the exam only covers what is sold today. Older interfaces, older memory types and older operating systems can still appear alongside modern ones, because a service technician meets whatever is actually on the bench.
Domains 7-9: Adapters, Ports and Power
Domain 7: Adapter Cards and Peripheral Devices
Understand what expansion hardware does and how it is installed and configured.
- Video, sound, network and other expansion cards
- Driver installation and resource assignment
- Common peripheral devices and their typical faults
Domain 8: Input/Output (I/O) Ports
Recognize ports and connectors on sight and know what each is for.
- Serial, parallel, USB and video connector identification
- Port characteristics, speeds and cable limitations
- Matching the right cable and port to the right device
Domain 9: Power Concepts and Power Supplies
Power is where the calculator earns its place, and where unweighted domains bite candidates who ignored them.
- Basic electrical relationships: voltage, current, resistance and power
- Power supply connectors, output rails and ratings
- Sizing a supply for the load it must carry
- Surge protection, battery backup and power-quality problems
Domains 10-11: Networking and Portables
Domain 10: Basic Networking Concepts Applicable to Computer Service
The scope is networking as it touches a service technician, not network engineering.
- Network interface hardware, cabling and connectors
- Basic addressing and connectivity concepts
- Sharing resources and verifying that a machine can reach the network
- Distinguishing a local hardware fault from a network problem
Domain 11: Portables
Laptops and other portable devices have their own parts, constraints and service rules.
- Portable-specific components: batteries, docking, displays and compact memory
- Power management and charging behavior
- Disassembly differences compared with a desktop
- Common field-service issues unique to mobile hardware
Domains 12-14: Troubleshooting, Operating Systems and Files
Domain 12: Troubleshooting / Preventive Maintenance / Security Measures
This domain ties the others together and rewards a methodical approach.
- A structured fault-isolation process: gather symptoms, narrow causes, test, confirm
- Preventive maintenance routines such as cleaning, updates and inspection
- Security measures at the service level, including protecting systems and data
- Recognizing which component a given symptom points to
Domain 13: Operating Systems (Windows 7, 8, 10, 11 / Linux / Apple macOS)
The issuer names specific platforms, so study them by name rather than treating "operating systems" generically.
- Windows 7, 8, 10 and 11: installation, configuration, utilities and common errors
- Linux basics as they apply to service work
- Apple macOS fundamentals
- Differences in how each platform handles drivers, updates and recovery
Domain 14: File Management
Know how files and storage are organized and how a technician protects them.
- File systems, directory structure and file attributes
- Copying, moving, backing up and restoring data
- Permissions and organization concepts
- Recognizing file-level problems versus hardware faults
Because Domain 12 spans every other area, practice questions from it are a good diagnostic of overall readiness. If you keep missing troubleshooting items, the weak link is usually in the underlying hardware domains rather than in the process itself. Candidates wondering how this stacks up against other entry-level IT exams can read How Hard Is the CST Exam?.
Pathways, Rollover and Renewal
Ways to qualify
- Standalone CST: no CETa required. Basic electronics preparation is suggested, not mandated.
- Journeyman path: requires CETa and at least two years of combined training and experience.
- A+ rollover: a valid CompTIA A+ (ce) qualifies you for the separate USD 80 rollover route. Lifetime A+ does not qualify.
Keeping the credential alive
| Requirement | Detail |
|---|---|
| Certification term | Four years |
| Maintenance form | Required each cycle |
| Continuing education | 10 contact hours per year (40 over four years) |
| Alternative to CE hours | Supervisor-completed employer verification |
| Maintenance fee | USD 25 per year (USD 100 per four-year cycle) |
Plan for renewal from day one. Logging continuing education as you go is far easier than reconstructing four years of activity at the deadline. If you are weighing whether the ongoing commitment pays off, see Is the CST Certification Worth It? and the career outlook in CST Salary Guide.
Sequencing Your Review Around the 14 Domains
Since the domains are unweighted, spend your time proportionally to your weaknesses, not to the topic's perceived importance. One sensible ordering follows how the material builds on itself:
Foundations
- Domains 1, 2 and 9: safety, assembly and power, since electronics fundamentals support everything else
Core Hardware
- Domains 3 through 6: boards, processors, memory and storage
Connectivity and Mobility
- Domains 7, 8, 10 and 11: adapters, ports, networking and portables
Software and Synthesis
- Domains 12 through 14: troubleshooting, operating systems and file management, then timed full-length practice
Troubleshooting comes late deliberately: it only makes sense once you know what can fail. Finish with a timed run of 80 questions in two hours at the CST practice test to rehearse the pacing, which works out to a bit over a minute and a half per question.
Frequently Asked Questions
The exam has 80 questions with a two-hour time limit. It is a proctored theory examination, and the passing score is 75%.
No. The assessment is theory only. Practical experience helps with scenario questions, but nothing is demonstrated on physical equipment during the exam.
ExamRoom.AI remote proctoring is arranged through ETA and adds a USD 16 two-hour proctoring fee on top of the USD 80 exam fee. The proctoring fee also applies to a free retake taken remotely.
Yes, a non-programmable scientific calculator is permitted, along with scratch paper. You must surrender used scratch paper, and photo ID is required to test.
Certification lasts four years. Standard maintenance requires the maintenance form, 10 continuing-education contact hours per year (40 over four years) or supervisor-completed employer verification, plus USD 25 per year (USD 100 per cycle).
Use this sheet as your checklist, then confirm each domain with targeted questions. For a broader orientation to the credential, start with What Is CST Certification? and, when you are ready to test your recall, head to the main practice test site.