Map twelve print quality symptoms onto the stage that produced them

short · 40 min · Objective 3.3

Task

Turn the seven-stage laser process into a diagnostic table, and prove it covers the symptoms by mapping twelve of them -- because a symptom mapped to a stage is a symptom mapped to a component.

Steps

  1. Write lab/print/stages.csv with header order,stage,what_happens,component listing the seven laser stages in order.
  2. Write lab/print/symptoms.csv with header symptom,stage,component,first_test with twelve rows, covering at least blank pages, all-black pages, toner that rubs off, a vertical white streak, a vertical black line, ghosting and repeating marks.
  3. For the repeating-marks row, record in lab/print/repeat.md how the interval between marks identifies which rotating component is at fault, and what you would measure.
  4. Write lab/print/consumables.csv with header printer_type,consumables covering laser, inkjet, thermal, impact and both three-dimensional types.
  5. Where a printer is available, print its own configuration or self-test page and record what it told you in lab/print/selftest.md -- page count, consumable levels and firmware version.

Verify

awk -F, 'NR>1 && NF>=4 {n++} END {print n" stage(s)"}' lab/print/stages.csv
awk -F, 'NR>1 && NF>=4 {n++} END {print n" symptom(s) mapped"}' lab/print/symptoms.csv
awk -F, 'NR>1 {print $2}' lab/print/symptoms.csv | sort -u | wc -l
grep -c . lab/print/repeat.md
awk -F, 'NR>1 && NF>=2 {n++} END {print n" printer type(s)"}' lab/print/consumables.csv

Seven stages in order, twelve symptoms mapped across at least four distinct stages, the repeat note present, and six printer types with consumables. If every symptom mapped to the same stage, the mapping has not been thought through.

Notes

The self-test page is the single most useful thing a printer can be asked to do. It bypasses the computer, the driver, the network and the queue in one step, and lesson 39 leans on it.

This is an independent study companion for CompTIA A+ Core 1 220-1201 and is not produced by or endorsed by CompTIA.