Mobile Devices and Printers
Two A+ Core 1 topics that are pure recall. The laser imaging process is asked in order almost every exam cycle, and the fault table is the shape most printer questions take.
Mobile Devices and Printers · firsttry.app/cheatsheets/mobile-and-printers · original reference written from published exam objectives. Not affiliated with any certification body.
The laser imaging process, in order
| Step | What happens |
|---|---|
| 1. Processing | The page is rendered into a bitmap in printer memory |
| 2. Charging | The drum is given a uniform negative charge |
| 3. Exposing | The laser writes the image, neutralising those areas |
| 4. Developing | Toner is attracted to the exposed areas |
| 5. Transferring | Toner moves from the drum to the paper |
| 6. Fusing | Heat and pressure bond the toner to the paper |
| 7. Cleaning | Residual toner and charge are removed from the drum |
Printer types
| Type | How it prints | Suits |
|---|---|---|
| Laser | Toner fused by heat | High volume office printing |
| Inkjet | Liquid ink sprayed onto paper | Low volume, photographs |
| Thermal | Heat on special paper | Receipts, labels |
| Impact / dot matrix | Pins strike a ribbon | Multipart carbon forms |
| 3D (FDM) | Melted filament laid in layers | Prototyping |
| 3D (resin) | Liquid resin cured by light | Fine detail models |
Printer faults
| Symptom | Usual cause |
|---|---|
| Toner smears or rubs off | Fuser not reaching temperature |
| Repeating marks down the page | Damaged drum. The spacing gives the roller size |
| Vertical white streaks | Toner low, or an obstruction on the transfer roller |
| Blank pages | Toner cartridge seal not removed, or no transfer charge |
| Ghosting | Failed cleaning stage or a worn drum |
| Paper jams repeatedly | Worn pickup rollers or the wrong paper weight |
| Garbled output | Wrong or corrupt print driver |
| Faded print | Toner low, or economy mode enabled |
Mobile connectors and sync
| Item | Detail |
|---|---|
| USB-C | Reversible, carries data, power and video |
| Lightning | Apple proprietary, being replaced by USB-C |
| NFC | A few centimetres. Payments and pairing |
| Bluetooth | About 10 metres for most classes. Peripherals and audio |
| Hotspot / tethering | Sharing a cellular connection |
| MDM | Central policy, app control and remote wipe |
| Synchronisation methods | To the cloud, to a desktop, or to an automobile |
| Remote wipe | Erases a lost device. Requires enrolment beforehand |
Exams covered
Now test yourself
Memorizing a table is a start. Practice questions are what make it stick, and every answer carries the full explanation.