Need help with old mag hps ballasts

[West]

I've got a couple of older magnetic hps ballasts I'm trying to get back into service to flower some autos.

Both ballasts will start mh bulbs but will not start a hps even after replacing ignitor with a supposedly good Phillips advance unit.

Is there a way to test a ignitor? If these ballasts will start mh bulbs doesn't that mean it has to be a bad ignitor?