Quote Originally Posted by silverhalides View Post
It now reads 0.00 no matter what density is placed under the read head. A calibration patch of around 3.00 density, placed under the read head, very briefly flashes a density near the calibration density (e.g. 2.93 or something in range), and then reads 0.00. It behaves the same on all seven transmission channels.
Is anyone familiar with this problem?
If you turn it off, then back on, does it still read 0.00, or does it show the hash marks which mean it has not been zeroed?

If the off/on cycle reads 0.00 immediately, it sounds suspiciously like the "zero" button is being held down constantly. If so, maybe working the button a number of times might free it up. Good luck.