Separate no power, no POST and no display on a machine you can safely stop

short · 45 min · Objective 5.1

Task

Run the three-question split on a real machine by creating each of the three states deliberately and safely, and record what the machine showed in each -- so the categories are observations rather than definitions.

Steps

  1. With the machine working, record its normal startup indications in lab/post/normal.csv with header indication,present,detail -- fans, lights, beeps, diagnostic LEDs, drive activity, image.
  2. Create the NO DISPLAY state by disconnecting the display cable only. Record the same table into lab/post/no-display.csv and note in the detail column what still proves the machine is running.
  3. Create the NO POST state by removing all memory with the machine powered off and unplugged. Power on, record lab/post/no-post.csv, and note what the board reported.
  4. Create the NO POWER state by disconnecting the mains at the wall. Record lab/post/no-power.csv.
  5. Restore everything, confirm normal startup, and write lab/post/split.md stating the one observation that distinguishes each state from the next, and how long the whole split took.

Verify

awk -F, 'NR>1 && NF>=3 {n++} END {print n" indication(s) at normal"}' lab/post/normal.csv
ls lab/post/no-display.csv lab/post/no-post.csv lab/post/no-power.csv | wc -l
awk -F, 'NR>1 && tolower($2)=="yes" {n++} END {print n+0" indication(s) still present with no display"}' lab/post/no-display.csv
grep -c . lab/post/split.md

Four or more indications recorded at normal, all three states captured, at least two indications still present in the no-display state, and the split note. If the no-display state shows nothing present, the machine was not actually running and the state created was a different one.

Notes

Remove memory with the machine unplugged, and put it back the same way. The point of the exercise is the board's reaction to a missing component, which is free to observe and costs nothing to reverse.

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