Hello midarq - by side lamp, I presume you mean the light on a Sony cover ? A flexible arm with light that lights up when swivelled upwards to illuminate the reader page ?
It can simply be the battery needs renewing - rechargeable ones are OK, although battery life is good on these lamps. The battery is changed through a flip lid in the left side of the cover - shouldn't break your nails, it opens fairly easily !
The other reason may be the bulb needs changing - haven't done this myself, but should be standard maintainance level..... I'll have a look tomorrow.
Try the battery first anyway, it's the most likely.
Hope this helps.
