Amiman wrote:
I know the general meaning of the word in English,
but exactly what does it indicate as a trade item ?

I guess a used computer would be classed as 'refurbished'
if it was cleaned up, had some defective or obsolete
components replaced and then put up for sale again. But a refurbished
motherboard ? Esp a model that was introduced
only a couple of months back ?

Are such items those that were damaged in shipping or had
some manufacturing defects and were repaired ? Are they
reliable ?

At best the products are brand new, unopened overstock returns from
distributors, or they've been very thoroughly repaired, with not only
the obvious defects corrected but also working components replaced
simply because they're known to have high failure rates, and the
circuit boards tested with automated equipment that pokes them all over
with needles to measure almost every circuit parameter. Such
refurbished products should last almost as long as brand new ones.
Unfortunately 'refurbished' usually means the product was repaired just
enough to get it to work again, and maybe the cabinet was cleaned up to
look pretty. Refurbishment sweat shops always do the latter, but so do
some large manufacturers, like Panasonic, which shiped 2 monitors in a
row that were in sorry shape - gouged cabinet front, cracked base,
wires dangling loose inside, large metal shield left out, bad solder
joints, picture way too dark. Apparently they refurbish their office
machines just as badly - very disreputable company.

Motherboards are commonly refurbished by replacing electrolytic
capacitors (known high-failure components), damaged MOSFETs (often
damaged by those capacitors) and any chips zapped by surges or static
electricity.