Oncidium care, what am I doing wrong?

[FranningtonBear]

I am an amateur windowsill grower based in the UK, mostly my orchids thrive on this regime.

I was given the NoID plant pictured below by a friend when she stopped flowering. I haven’t seen her in bloom but I’m reasonably confident she is some type of Oncidium hybrid (did I mention I am an amateur?).

When this plant was given to me she had only two pseudobulbs, I repotted her into a slightly larger pot with fresh medium (a medium grade orchid bark) and found she had very few live roots. Since repotting around 18 months ago she has produced a huge amount of root growth and developed 6 further pseudobulbs making 8 in total. I keep her on a bright, north facing windowsill and she appears to be healthy but no sign of flower spikes… what am I doing wrong?