A practical guide to mobile device repairs: what is worth fixing and what is not

Almost every phone and tablet that arrives at the workshop has one of five faults. Knowing which one you are dealing with — and roughly what the work involves — makes it much easier to decide whether to repair or replace a device.

1. Screens

A cracked screen is the most common repair of all. What matters is whether the damage is limited to the outer glass or extends to the display and digitiser underneath. Touch dead-spots, lines, black patches or a screen that flickers all point to display damage rather than cosmetic glass damage. On most modern handsets the glass and display are bonded as one assembly, so the assembly is replaced rather than the glass alone.

Signs it needs doing sooner rather than later: exposed sharp edges, ingress paths for dust and moisture, and touch areas that no longer respond.

2. Batteries

Batteries are consumables. After a few hundred charge cycles capacity drops, and the symptoms are predictable: sudden shutdowns at 20–30%, throttled performance, heat during charging, or a device that only stays alive on the cable. A swollen battery lifting the screen or back panel should be treated as urgent and stopped being charged.

3. Charging ports

Charging faults are often not the port at all. Lint compacted into the connector, a failing cable, or an underpowered adapter cause a large share of "won't charge" reports. When the port itself is at fault — loose fit, charging only at an angle, intermittent connection — it is replaced at board level and tested under real charging load.

4. Cameras, speakers and microphones

Blurry or shaking photos, a rattling rear camera, muffled call audio or a microphone nobody can hear you on are usually module-level replacements. Where several audio functions fail together, the fault is more likely on the board's audio circuit than in any one module — that needs proper diagnosis rather than parts swapping.

5. Liquid damage

Liquid damage is a race against corrosion. Rice does nothing useful. The device should be powered off, kept off the charger and brought in as soon as possible so the board can be opened, cleaned ultrasonically and inspected under a microscope before corrosion spreads across the circuits. Devices treated within a day or two have a far better outcome than ones that were used for a fortnight afterwards.

Repair or replace?

A sensible rule of thumb: repair when the device otherwise does everything you need, the fault is isolated, and the repair costs a fraction of a comparable replacement. Lean towards replacement when the device no longer receives security updates, when several unrelated faults have stacked up, or when liquid corrosion has spread widely enough that reliability cannot be promised.

Before any repair

• Back up. Always, even for jobs that do not touch storage.
• Note down exactly when and how the fault appeared — it genuinely shortens diagnosis.
• Mention past repairs and liquid contact.
• Remove cases, SIM trays and memory cards you want to keep hold of.

Quality workmanship, tested parts and honest advice on whether a device is worth fixing — that is what our Dundee workshop is set up to give you.