I recently bought a replacement laptop PC from Dell and was happy to see that its AC/DC power adapter had the same ratings as the ones I had from two now-defunct Dell laptops (19.5 V, 2.3 A/45 W).

One of the advantages of notebook PCs is that they can be used in places where power cannot be secured due to the built-in battery. However, there are times when problems occur with older models, and ...