Como dizer "caneta falhando" em inglês

Hi there!

I think you can use: My pen isn't working!

hugs,
Eduardo

my pen is running out of ink - está acabando a tinta

Mas não acho que se encaixaria muito bem, pois uma caneta pode estar falhando mesmo cheia.
Para dizer "falhar", poderia sugerir dried out, conforme o artigo:
http://www.wikihow.com/Restart-a-Dry-Ball-Point-Pen

"My BIC ballpoint pen doesn't write. (I need another one. Here <hand reaches out to other hand>... 10 cents <slaps coin on palm of hand>... go buy me new pen.)"

My pen is scratchy. (UK)

And also, my ballpoint pen isn´t working/won´t write/it´s "dead" (more often than not, it´s clogged up or dried out)/fails when I need it most/stopped working in the middle of a word, etc.

Dried out - suggest that the ink inside the pen has dried out "secou", but in the sense of "ressecou". Then with a little bit of heat, it gets back to normal.