5V, 4.5V, PFC, non-PFC and common-cathode LED display power supplies: what each is for, what goes wrong if you swap them, and what to check before ordering.

Why 16:9 matters for LED video walls, how indoor and outdoor module sizes affect the ratio you can build, and how to size a wall that fits your content.

Why grey-market LED modules cost more than they save: mixed LED bins, weaker driver ICs, no warranty or matching spares, GST credit risk, the break-even maths, and five checks before you buy.

How to choose LED pixel pitch: viewing-distance rules, resolution maths, and indoor vs outdoor picks, with worked examples for P1.5, P2.5 and P4.

GI or die-cast aluminium? Both are used on outdoor hoardings. A practical comparison of weight, accuracy, rust, cost and cabinet sizes, plus the mistakes to avoid when ordering LED cabinets.