Well, I'm not that well rehearsed with the technics of the heads, but I've had one that deteriorated within 5 or 6 shortish runs...but it had done a massive, massive amount of work in fairness, but if all results are consistent and nothing has changed on your programmes etc, it's not looking good.. However, hope I am wrong of course.
Anyone have any knowledge regarding testing the head..voltages etc?? have you tried speaking to The Plotter Doctor at all.. they helped me more than they'll ever know quite a few years back.. great guys!
Titch