Komori L528 1992 all unit ink keys blinking problem

We are facing a problem in our komori lithron L528 the all unit ink key blinking . checked all power supply in PQC pannel found all ok.also checked all connectors if any one have any idea how to solve it please reply

 

Hi sir;

Test this please;

Check ON-OFF of Relays CR1 To CR4

Check ON-OFF of Relyas 1C-1.2 TO 4c-1.2

Check if LED D1 TO d6 of the key interface unit(SP-00860) Lights up respectively

Check for wiring system connector CNA6+CNA7 for faulty pin contact

Check for switchs if is o.k or faulty by continuity test at connector or switch terminal

Check earthing of the wiring system +wiring system for false contacts, and clean with special contacts cleaner.