Prove the self-test page divides the problem in one step
Task
Demonstrate that a printer's own self-test bypasses the computer, the driver, the network and the queue, and build the one-question rule that directs the next hour.
Steps
- Print the printer's own configuration or self-test page from its control panel, and record what it told you in
lab/pfault/selftest.csvwith headerfield,value-- page count, consumable levels, firmware, network configuration. - Write
lab/pfault/bypasses.csvwith headerlayer,bypassed,whylisting what the self-test skips: application, driver, spooler, network, and the device's own network stack. - Print the same document from two different machines and record any difference in
lab/pfault/two-machines.md, stating what a difference would have implicated. - Write
lab/pfault/rule.mdstating the one-question rule -- one user or everyone -- and what each answer directs you to look at. - Write
lab/pfault/symptom-stage.csvwith headersymptom,layer,first_testwith at least eight rows, at least three of which are queue, driver or network rather than the marking engine.
Verify
awk -F, 'NR>1 && NF>=2 {n++} END {print n" self-test field(s)"}' lab/pfault/selftest.csv
awk -F, 'NR>1 && NF>=3 {n++} END {print n" layer(s) bypassed"}' lab/pfault/bypasses.csv
grep -c . lab/pfault/two-machines.md
grep -Eic 'one user|everyone|everybody' lab/pfault/rule.md
awk -F, 'NR>1 && NF>=3 {n++} END {print n" symptom(s) mapped"}' lab/pfault/symptom-stage.csv
awk -F, 'NR>1 && tolower($2)!="engine" {n++} END {print n+0" non-engine symptom(s)"}' lab/pfault/symptom-stage.csv
Three or more self-test fields, four or more bypassed layers, the two-machine note, the one-question rule naming both answers, and eight symptoms of which three or more are above the device. A symptom table where everything is the marking engine has forgotten that most printer tickets are not printer faults.
Notes
The self-test page is the cheapest diagnostic split in this whole domain. It costs one sheet of paper and eliminates four layers at once.
This is an independent study companion for CompTIA A+ Core 1 220-1201 and is not produced by or endorsed by CompTIA.