i picked up a hardinge hnc lathe with a ge mark century 550 control. I got her fired up after tracking down the cause of a burnt fuse (seized fan), and it slowly began to work. at first, it would only move in small increments every time i fliped the jog switches in either jog mode. after playing with it, it began jogging as it was supposed to. i was then able to set tool ofsets, get the turret to move, etc all in mdi mode. i hit the ref zero button and it started moving, then before it stopped, the machine completely shut down. the green power button was still backlit and the fans were on, but everything else was dead. No fuses were blown as far as i could tell (i think i found them all). Air pressure is about 90psi so i dont tihnk it's that, but it is acting like it shut down due to low air pressure. i was going to track down the air pressure sensor and try bypassing it to see if that's the problem but i havent gotten that far yet. Any ideas?
side note, alot of the buttons were frozen or the backs poped off the contact blocks, so i replaced a bunch of them with momentary push buttons. not sure if that is related to this issue. The ones i replaced were x home, z home, gaurd open, stop auto mode, read error, and super precision mode. When i first fired up the machine, everytime i pushed the x or z home buttons, the machine would shut down, similar to what it did this time, only now i cant get it to start back up again.
Just curious if there is something simple that i'm overlooking, or if there is a common problem similar to what i'm experiencing.
Thanks,
Dan