I had some strange issues copying text out of a PDF on my iPad (I always got a bunch of ????), so I decided to run my pdf through xpdf to see if that would fix things:
pdftops naughty.pdf intermediate.ps
pstopdf -o good.pdf intermediate.ps
After the first command ran though, I got the following error:
Config Error: No display font for 'Helvetica-Bold'
Config Error: No display font for 'Times-Bold'
Config Error: No display font for 'Times-BoldItalic'
Config Error: No display font for 'Times-Italic'
Config Error: No display font for 'Times-Roman'
On a Linux installation, I'd typically resolve this by installing a font package, but I'm not sure what to do on OS X.
Best Answer
The fonts are almost certainly installed and available to MacOS: it's more likely a question of whether the fonts are actually embedded in the PDF, or other font issue.
If you were having text problems in the original PDF, and errors relating to fonts when converting to PS, then there's likely something wrong with the source PDF.
You might want to try some of the xpdf
pdftopsoptions, like specifying PS Level 3-level3, or substituting base fonts-noembt1.