On 4/29/2014 8:30 AM, Apple_Tester wrote:
Hi!
Short circuited diode, glass enclosure.
The only markings are 2 and 18.
Zener 18V?

Hello,

If you could re-post, mentioning the make and model of the item the
diode belongs to, and the circuit location, it would help all identify
the part for you, as someone might have the schematic, and be able to
look it up.

Regards,
Tim
Bristol Electronics