PJ2787-02 web offset ink ink failure and troubleshooting

Fault: When the PJ2787- 02 extension runs and connects (AB feed, A set, B set, B online operation of the folding machine), the B group ink roll will not run.

Analysis: In the past, this situation was generally caused by the fact that the ink-supply control transformer secondary fuse Ful0B was blown, the control transformer primary fuse Fu24B, Fu32B was blown, and it was not the set of open points used by the relay KAllB that were bad or loose. Based on the above experience, we first checked the Ful0B, Fu24B, and Fu32B fuses and found no problem. Then we have no problem with the multimeter's electric resistance measurement check for a set of open points (701B and 704B terminals) used by the relay KAllB. After careful examination of the above items, the problems found this time are different from before.

I reopened the electrical drawing, found electrical control circuit 26 (control circuit) ink given control circuit, re-sent power, measured the voltage at the input of the ink supply panel (211B and 212B) with the multimeter's AC voltage level and used the DC gear. Measurement circuit board outputs (701B and 705B) have no voltage. It turns out that the given circuit of the ink and ink has failed. Which part is broken? After electrifying the voltage on the board, the output voltage of the VClB rectifier bridge is measured. The voltage across the voltage regulator ICIB is insufficient to determine that the ICIB is broken.

Troubleshooting: Buy the same type of LM317 regulator block, troubleshooting.

Emergency measures: If at the time can not buy LM317 regulator block, and must be used (AB feed, A unit, B unit, B folding machine online operation), you can first remove KAllB (701B and 704B) Short-circuit the two points on the KAllA (701A and 704), you can use this mode of operation, but do not change the mode of operation before it is restored.