Lesson 5: Mobile Device Troubleshooting Challenge

Core path: 42 minutes

Core 1 objective 5.4 is a symptom objective. You are expected to separate similar-looking failures without random part replacement or destructive resets.

Symptom matrix

Use the supplied evidence packets to diagnose at least six of these:

• poor battery health;
• swollen battery;
• broken screen;
• improper charging;
• poor or no connectivity;
• liquid damage;
• overheating;
• digitizer issues;
• physically damaged ports;
• malware indicator;
• cursor drift / touch calibration;
• unable to install a new application;
• stylus does not work;
• degraded performance.

Ticket A: swollen battery

Evidence:

• case is separating near the battery area;
• trackpad is lifting;
• battery runtime is poor.

Stop normal service. Do not press the case closed, puncture the pack, or continue charging it. Follow the approved battery-hazard procedure.

Ticket B: damaged charging port

Evidence:

• known-good charger works on another compatible device;
• connector only charges when physically held at an angle;
• visible port damage exists.

The charging problem now has strong physical-port evidence.

Ticket C: touch is inaccurate

Evidence:

• display image is normal;
• finger/stylus input lands away from the intended point;
• no cracked screen is visible.

Investigate digitizer/calibration/input configuration before replacing the display panel blindly.

Ticket D: application will not install

Evidence:

• network works;
• device has insufficient free storage in the supplied state;
• application requires more free space than available.

The install failure is not proof of malware or bad Wi-Fi.

Ticket E: device is slow and hot

Evidence:

• storage is nearly full;
• multiple background applications are active;
• CPU use remains high;
• battery is not swollen in the scenario.

Overheating and degraded performance can share a workload/resource cause. Measure before replacing hardware.

Ticket F: suspicious mobile behavior

Evidence:

• unexpected pop-ups began after an unapproved application install;
• network/data use increased;
• device still connects normally.

Treat malware as plausible, preserve the evidence, follow the approved mobile-security/remediation procedure, and avoid collecting personal credentials or private content.

Ticket G: liquid exposure

Evidence:

• user reports liquid reached the keyboard/ports;
• device is currently powered off.

Keep it powered off and follow approved service/escalation procedure. Powering it on repeatedly is not a diagnostic technique.

Ticket H: stylus does not work

Evidence:

• finger touch works;
• stylus is compatible with the model;
• stylus battery/charge is depleted in the supplied scenario.

Stay at stylus/pairing/power scope before replacing the digitizer.

Service record

For each selected ticket document:

symptom:
known-good evidence:
strongest theory:
alternative theory:
controlled next check:
safety/data boundary:
expected result:
verification after repair:

Week 5 completion criteria

You should now be able to connect:

1.1 hardware/replacement
→ 1.2 accessories/connectivity
→ 1.3 mobile network + application support
→ 5.4 troubleshooting

The goal is not to memorize fourteen symptoms. The goal is to know which boundary each symptom makes worth testing first.