Hi. I happened strange accident with CTP Screen 4300S.
In Friday morning 31 January, customer call me and say: "The CTP works on the halfspeed".
When I came in print house in 16:00, I saw CTP works with speed 21 plates in hour and all channels work correctly, after self calibration, but Iop/IopMax 2 channels (N11, and N18) is too low, 6,4% and 7,9% according. I thought, the problem was with these 2 channels but I have only one diodе. I proposed to customer come in Tuesday 4 February and change 2 diodes together.
When I came in Tuesday, I saw channels 11 and 18 is too low and channel 5 is broken and Iop/IopMax -100% and Iop=Iopd, Iopd=1072mA. The Iop and Iop/IopMax channel 5 according, deviated in time autocalibration from +50% to -100%.
Before replacing diodes I brushed all lenses and radiator on the record head from dust. I have changed diode in channel N5 (because I think this diode is broken) and diode N11 (because Iop diode is too high). After I install new Iopd from service menu and calibrate channel N5 first, and channel N11 second. The calibration was without errors. After all operations I calibrate all diodes (32) and CTP gave the message - "the channels 3, 25,30,31 faulty or too low". I saw Iop in service menu-RH parameters-Iop, Iop/IopMAX and absolutely ALL channels decreased nearly 70-120mA, and Iop/IopMAX decreased 50-70%. But the diodes in 5 and 11 channels was Iop/IopMAX=100%. However in channel 11 IopMAX=Iopd=1017mA (I think this situation is abnormal for new diode).
After this incident, I replaced new diode in channel 11, and install old diode. Install old value for Iopd, too. After these actions I calibrate all channels and see - values for all channels returned to normal values.
What happened? This new diode is defective? Or this machine has a problem in other parts?
In Friday morning 31 January, customer call me and say: "The CTP works on the halfspeed".
When I came in print house in 16:00, I saw CTP works with speed 21 plates in hour and all channels work correctly, after self calibration, but Iop/IopMax 2 channels (N11, and N18) is too low, 6,4% and 7,9% according. I thought, the problem was with these 2 channels but I have only one diodе. I proposed to customer come in Tuesday 4 February and change 2 diodes together.
When I came in Tuesday, I saw channels 11 and 18 is too low and channel 5 is broken and Iop/IopMax -100% and Iop=Iopd, Iopd=1072mA. The Iop and Iop/IopMax channel 5 according, deviated in time autocalibration from +50% to -100%.
Before replacing diodes I brushed all lenses and radiator on the record head from dust. I have changed diode in channel N5 (because I think this diode is broken) and diode N11 (because Iop diode is too high). After I install new Iopd from service menu and calibrate channel N5 first, and channel N11 second. The calibration was without errors. After all operations I calibrate all diodes (32) and CTP gave the message - "the channels 3, 25,30,31 faulty or too low". I saw Iop in service menu-RH parameters-Iop, Iop/IopMAX and absolutely ALL channels decreased nearly 70-120mA, and Iop/IopMAX decreased 50-70%. But the diodes in 5 and 11 channels was Iop/IopMAX=100%. However in channel 11 IopMAX=Iopd=1017mA (I think this situation is abnormal for new diode).
After this incident, I replaced new diode in channel 11, and install old diode. Install old value for Iopd, too. After these actions I calibrate all channels and see - values for all channels returned to normal values.
What happened? This new diode is defective? Or this machine has a problem in other parts?
