Technician Procedures

This page has two parts. Sections 1 to 6 are troubleshooting, which ETA lists under Competency 6 (6.2, 6.6 and 6.8): a systematic method for finding and fixing faults, the thing that separates a technician from a parts-swapper. Sections 7 to 17 are Competency 21, Technician Work Procedures: the work order, the estimate and test plan, service literature, parts cross-referencing, the service record, the invoice, productivity, field service and project management, followed through one worked service ticket and ending with a printable blank ticket.

The troubleshooting mindset

Part 1, Competencies 6.2, 6.6 and 6.8. Effective troubleshooting is narrowing the possibilities efficiently. Every measurement you take should cut the number of suspects roughly in half, not just confirm what you already believe. The goal is to locate the fault with the fewest tests, then verify the fix actually solved the reported problem — and didn't create a new one.

A systematic procedure

1. Identify the symptom. Get a clear, specific description of what's wrong. "It doesn't work" isn't a symptom; "no audio output but the power LED is on" is.
2. Gather information. What changed? Recent repairs, a power surge, dropped unit? Check the obvious first — power, fuses, connections, settings.
3. Form a hypothesis. Based on the symptom and how the circuit works, list the stages that could produce it. Use the block diagram.
4. Localize the fault by dividing the system — test at the midpoint to cut the suspect area in half (the half-split method, below).
5. Isolate to the component. Within the bad stage, measure to find the specific failed part.
6. Repair using correct procedures and replacement parts.
7. Verify & test. Confirm the original symptom is gone, the unit works fully, and no new fault was introduced.

Flowcharts. Competency 6.9 asks you to explain the methods of using flow diagrams and charts. A flowchart draws a procedure as standard shapes joined by arrows, so a reader can follow the steps and the decisions without reading paragraphs. ANSI set the symbols in the 1960s, and the current standard is ISO 5807 (1985, last reviewed in 2019).

Using one. Start at the terminal, carry out each rectangle in turn, and at each diamond make the measurement, answer the question and follow the arrow for your answer. Written as a flowchart, the systematic procedure above becomes a troubleshooting tree: a diamond might ask "Is the 12 V rail present at its test point?", its "no" arrow leading to the supply and its "yes" arrow on to the next stage. Because every branch is drawn, no check is skipped, and the path you took is a record of what you measured.

The half-split method

When a signal passes through a chain of stages, half-splitting is the fastest way to find the dead stage. Instead of testing every stage from the input, you test in the middle first. The result tells you which half the fault is in, and you repeat — each measurement halves what's left.

Signal tracing vs. signal injection

Both home in on the same answer from opposite ends. The half-split method tells you where to start tracing or injecting so you reach the fault faster.

Common fault patterns

Good measurement practice

Trustworthy troubleshooting depends on trustworthy measurements: set the meter to the correct function and a range above the expected value, observe polarity on DC, account for meter loading on high-impedance nodes, and always compare against the expected value from the schematic or service data. A reading only means something relative to what it should be.

Competency 21: technician work procedures

Sections 1 to 6 are troubleshooting, which ETA lists under Competency 6. From here on the page is Competency 21.0, Technician Work Procedures: the business side of a repair, from the moment a customer hands over a unit to the moment they pay for it. These are ETA's nine items, in ETA's words, and where each is taught:

The job really does include this. The Bureau of Labor Statistics lists the duties of electrical and electronics installers and repairers, and two of them bracket the repair itself: “Discuss problems and requirements with customers” at the start, and “Keep records of repairs, tests, parts, and labor hours” at the end.

One ticket, start to finish. Sections 8 to 13 follow a single repair at a made-up shop for a made-up customer: a 13.8 V, 30 A linear bench power supply that blows its line fuse the moment it is switched on. The ticket runs intake, estimate, service literature, parts, repair and test, service record, invoice. Every dollar figure is an example: the labor rate ($85.00 an hour), the tax rate (7%) and the parts prices were picked to make the arithmetic clear. None of them is an industry standard, and real rates and tax rules are set by the shop and by the law where it operates.

Intake: opening the work order

The work order (the ticket) opens the job and travels with the unit. Field and industrial technicians work from them too: O*NET's task list for commercial and industrial equipment repairers starts with “Examine work orders and converse with equipment operators to detect equipment problems.” At intake, write down:

• The customer and how to reach them for approvals.
• The unit: make, model and full serial number, copied from the rating plate. The serial number decides which service literature applies (section 10).
• The complaint, in the customer's words, plus what you learn by asking: when it fails, how often, and what changed. This is the first step of the systematic procedure in section 2: “It doesn't work” isn't a symptom.
• What came in and its condition: accessories, and any damage already there.
• What the customer authorizes: usually diagnosis only, at a stated fee, with a call before any repair. California, for example, requires an electronic repair dealer to tell the customer the diagnostic fee in writing before the work; for a unit brought in to the shop, that is when the shop accepts it.

The estimate and the test plan

Competency 21.7 asks you to explain estimate concepts for service work, including test planning. An estimate prices the job before the work: the labor hours for diagnosis, repair and testing at the shop's rate, the parts, and tax where it applies. You cannot price a repair you have not found, so diagnosis comes first and is usually charged for: California's rule lets the dealer charge a reasonable fee for determining the malfunction and preparing the written estimate.

Approval. California's rules for electronic and appliance repair dealers, quoted here as one state's example (check the rules where you work), say: give the customer a written estimate before doing any repair; don't charge for work or parts beyond it without the customer's prior consent; and if that consent is given orally, note on the invoice the date, the time and the name of the person who gave it.

The test plan. A test plan lists the checks that will prove the repair: what you will measure, against what figure, and in what order. For equipment with a service manual, start from its own procedures: a 1990 Hewlett-Packard service manual, for example, has a section of performance tests and a section of adjustments. The tests take bench time, so they belong in the estimate.

Ticket 1047's test plan, written before the repair: bring the supply up slowly on a variac or through a series lamp; check 13.8 V with no load; check that it holds under a load near its 30 A rating; check the output ripple on the scope against the service manual's figure; and switch it on and off several times to prove the original complaint is gone and the fuse holds.

Service literature and the maker's help desk

Competency 21.2 asks how to procure service literature. Before you measure anything you need to know what the circuit should do, and that comes from the literature. The usual sources:

Match the literature to the unit. Makers change products during a run. The Hewlett-Packard manual says it applies directly to instruments with a stated serial-number prefix, and that it is updated for a new prefix only for parts compatibility. Compare the serial number on your ticket with the range the manual covers before you trust its parts list.

The maker's help desk. Competency 21.6 asks how to contact product makers' help desks and service departments. Call prepared:

• Try the self-service fixes first. Lenovo's list starts with checking the cables and power switches, then updated firmware, then the support portal.
• Have the identity of the unit ready: model number, full serial number and firmware level (Lenovo), so the representative can, for example, check its warranty status (Keysight's instructions).
• Have the evidence ready: error messages and logs (Lenovo), and the steps that reproduce the fault (Fluke Calibration's support team). Their manager also advises being near the equipment when you call, because support may ask you to try things.
• Know the other path: sending the unit back. O*NET lists sending defective units to the manufacturer or to a specialized repair shop as a task for industrial repairers.

Parts: locating and cross-referencing

Competency 21.3 asks you to describe locating and cross-referencing parts and products. Locating starts in the service manual's replaceable-parts list, which ties each reference designator on the schematic to a part and its ratings. The maker's own part may still be available; if it isn't, a distributor's cross-reference tool (DigiKey, for example, has one) lists alternates for a part number. Goldwasser warns that some parts are usually custom, and those have to come from the maker.

A cross-reference only proposes a part; you still have to judge it. Goldwasser's rule for transistors and thyristors is that substitutes will generally work as long as their specifications meet or exceed those of the original, and for rectifiers, equal or better PRV, maximum current and recovery time. For safety-related parts, such as flameproof resistors and some types of capacitors, his answer is that an exact replacement is needed. What to check, by part:

Why a capacitor's temperature rating matters: DigiKey's selection guide gives the “rule of 10” that many capacitors follow, service life doubling for every 10 °C reduction in temperature. Heat shortens an electrolytic's life, so the temperature rating is part of the match.

Repair, test and the service record

The repair itself follows sections 1 to 6. Two habits from there matter for the paperwork: find why the part failed, not just which part failed, and run every check in the test plan, writing each result down as you go.

Competency 21.4 asks for the purposes and requirements of proper record keeping and report generation. The BLS duty quoted in section 7 names the contents: repairs, tests, parts and labor hours. O*NET's industrial repairers “Maintain equipment logs that record performance problems, repairs, calibrations, or tests”, and its tower and radio installers “Complete reports related to project status, progress, or other work details, using computer software.” A good record serves four readers:

• The invoice is built from it: every labor line and every part on the bill should trace back to an entry.
• The customer gets proof of what was done, and of who approved any extra work and when.
• Warranty: California's invoice rules, for example, require each part to show whether it was under warranty or charged.
• The next technician, who may be you when the unit comes back, needs the measurements, the parts (substitutes included) and the test results.

The invoice

Competency 21.1 asks for the major invoice and billing concepts of a service business. An invoice itemizes: each labor line with its hours and the rate, each part with its price, then tax and the total. California's rules for electronic repair dealers, as one example, require the invoice to itemize each part replaced (showing warranty or charge for each), to itemize and describe the labor, and to state which parts are used or exchanged rather than new.

Two ways to bill labor. Bill the hours actually spent, or bill a standard (flat) time for the job: NetSuite's article on technician productivity describes billing customers on average, flat or industry-standard hours, which a technician can beat. Tax depends on where you are: California does not tax repair labor, while in Louisiana labor to repair tangible personal property is generally taxable. That is why this page's tax line is labelled as an example.

Productivity: individual and department

Competency 21.5 asks how to calculate individual and department productivity for a specific period. This page uses the definitions in NetSuite's article on technician productivity:

• Productivity = hours spent working on jobs ÷ hours clocked in × 100%.
• Efficiency = hours billed ÷ hours actually spent × 100%. Billing standard (flat) hours lets a fast technician run above 100%.

For a department, pool the hours for the period: total hours worked on jobs divided by total hours clocked in.

A related figure is the average time per job: 6 jobs in an 8-hour shift is 8 ÷ 6 = 1.33 h, which is 1 hour 20 minutes (0.33 h × 60 = 20 minutes).

Field service versus shop service

Competency 21.8 asks for the field procedures that may differ from in-shop routines. BLS says many repairers work in repair shops or factories, some work outside in all types of weather, and travel to job sites may be required. What changes when the bench comes to the customer:

Project management: the bigger jobs

Competency 21.9 asks you to explain project management and list the steps to follow to achieve maximum results. Some jobs are projects rather than repairs: installing radios in a fleet of twelve vehicles, say. The Project Management Institute (PMI) groups project work into five process groups. The descriptions below follow PMTI's guide to them:

A printable blank service ticket

The ticket below has a place for every stage in sections 8 to 13. Print it blank and fill it in by hand for practice, or use it as a checklist against the forms your shop uses. The button prints the ticket alone; printing the page from the browser prints the whole guide.

Print the blank ticket