Anyone seen this problem: Have a 5350 that never shows when the Cyan toner is low or empty, also doesn't show up on the Status Page under the toner gauge, they are using Kyocera toner and it has the latest FW installed, the Cyan seems to print fine on prints and pictures though.It adds the toner ok also, is it toner sensor, Dev PWB C, Drum PWB C or could it be Drum Relay PWP? Printer has 62,000 color and 31,000 mono prints on it. Even though all 4 toner cart. are genuine OEM kyocera, thier is a warning by the Toner Gauges on the status page that says "Warning We recommend the use of our own brand supplies" I called Kyo Tech. Supp. but of coarse they never heard of this problem B4. Any help would be appreciated.

We ran into something similar on the TASKalfa machines about a month/maybe 2 ago. Apparently a bad batch of toner cartridges were sent from overseas with no RFID chips in them. So toner worked just fine in the machine. But the machine flashed up NON-OEM TONER INSTALLED warnings and on the status page it wouldn't show status. So originally after a little discussion on here we though maybe our RFID board in the machine went out. But apparently it became a bigger problem Kyocera later found out on their end.

Again it was on the Kyocera MFPs but pretty much same problem as you described.