Week 01 · lesson
Lesson 5: Your First Service Ticket
This is the first time you put the technician process together.
You are not trying to prove that you can guess the failed part. You are trying to show that your diagnosis follows from evidence.
The scenario
A desktop user reports:
"It turns on, but nothing works."
Your supplied evidence says:
- power LED turns on;
- case fans spin;
- monitor is powered;
- monitor shows No Signal;
- keyboard LEDs flash briefly at startup;
- no operating-system screen appears;
- the system recently had a graphics card removed and reinstalled.
Step 1: identify the problem
Rewrite the complaint in technician language.
A useful problem statement is:
System appears to receive power but produces no visible display output during startup after recent graphics-card service.
That is narrower than "nothing works."
Step 2: establish a theory
Create at least three plausible theories.
Examples:
- display cable is connected to the wrong output;
- discrete GPU is not fully seated;
- GPU auxiliary power is disconnected;
- RAM was disturbed during service;
- monitor input selection is wrong.
Do not list ten random parts. The recent change matters.
Step 3: choose the least invasive test
A good test changes as little as possible.
Reasonable order:
- verify monitor input and cable;
- verify correct graphics output;
- inspect GPU seating and power with system safely powered down;
- inspect diagnostic indicators;
- continue deeper only if evidence requires it.
Why this order?
Because opening the system and reseating hardware creates more risk than checking the external display path.
Step 4: document your evidence
Use this ticket structure:
User report
What the user says happened.
Observed evidence
What you actually verified.
Recent changes
Anything installed, removed, updated, moved, or damaged.
Theory
The failure you currently think best explains the evidence.
Test
What you will do to challenge that theory.
Result
What happened after the test.
Action
What you changed, if anything.
Verification
How you proved normal functionality returned.
Prevention / follow-up
Anything the user or technician should do next.
Lab variation A: wrong output
If the supplied evidence reveals that the display cable was connected to an inactive motherboard video output while a discrete GPU is installed, document why moving the cable is a justified test.
Do not write:
Fixed monitor.
Write what changed and what verification proved.
Lab variation B: GPU power
If the GPU is seated but its required auxiliary power connector is disconnected, explain why fans and case LEDs can still operate even though graphics output fails.
The entire PC does not need to be unpowered for one subsystem to fail.
Lab variation C: RAM disturbed
If the graphics path checks out and a diagnostic indicator points toward memory, inspect RAM seating using ESD-safe procedure.
Again, follow evidence. Do not reseat every component because you ran out of ideas.
Verification matters
A repair is not complete because the screen lights up once.
Verify enough of the original complaint to show the system is functional:
- POST completes;
- firmware or boot logo appears;
- operating system loads when expected;
- display remains stable;
- no new diagnostic indicators appear.
Week 1 deliverable
Submit or preserve:
- technician workspace checklist;
- component census;
- port/interface map;
- firmware/POST observation;
- completed service ticket.
Your ticket should clearly separate what the user said, what you observed, what you believed, and what the test proved.
That separation is the habit we care about.
Next week we go deeper into motherboards, processors, RAM, storage, power, and compatibility.
Read it. Prove it.