As I have said in previous posts: given the state of hybridization and
prevalence of good quality Phalaenopsis hybrids on the market (due to
cloning and the number of years these plants have been bred and
studied), there is little reason to struggle with an ailing/declining
plant other than for the experience, or because of emotional
attachment.

In orchids, because of their physiology, yellow streaks in a
Phalaenopsis are unlikely to be the result of nutrient deficiency
unless it has had no fertilizer at all for many months (and if this is
one that has only spent a few weeks in your office, you can be sure it
was fed regularly at the nursery where it was grown). It is more
likely to be the result of disease (fungal in this case), excessive
moisture at the roots or stress (light levels too low, nights below 60
degrees, and more). If you took this plant home months ago in a rescue
attempt, and have not fed it, than it could possibly be nutrient
deficiency, most specifically Iron, Zinc, or Magnesium. However it
could still be stress and/or disease if the needs of Phalaenopsis are
not understood.

Please click on "techniques/culture" on the right side of the page and
read the culture sheet for Phalaenopsis. Also check out the texts on
watering and repotting. These are really important for keeping the
roots alive and healthy (and healthy roots are the most important
aspect of maintaining the plant in the long term). Overwatering and
underwatering are mistakes in frequency and method of watering, and
overwatering in particular is the source of many (if not most) of the
difficulties people have in growing orchids. Pot type, pot size, type
and age of potting material have a strong affect on the rate of drying
of the roots. Light intensity, air movement and temperature do as
well. This is not as complicated as it sounds, and the broad guideline
of watering approximately once a week usually works. Talk to your co-
worker about how she determines when to water, and try to give your
plant the same level of light (an Eastern window with a light curtain
is good as well, adapted these plants can take some morning sun). Look
for a fertilizer that is evenly balanced, and has a list of "micro-
nutrients" in the label. Feed every second or third watering with a
solution mixed at half the recommended strength. You need not use a
food that claims to be specifically for orchids.

A few pictures of the plant might help me determine if the problem is
disease. If it is not there is no reason to think you cannot bring the
plant back to health and bloom it!