Siemens OP17 HMI
With any electronic devices we always recommend routine maintenance and servicing to avoid costly breakdowns. This can be a simple visual inspection, cleaning or replacement of common time degradable components.
This Siemens Operator Panel OP 17/DP12 6AV3617-1JC30-0AX2 is a classic example of being left to do its job since 1997 without any maintenance.
You would be right in thinking “What maintenance does a keypad screen really need?”, however when the covers are removed the implications of no maintenance become quickly apparent. This unit was behaving unpredictably and not accepting input of data from the keypad. The initial thought was maybe a failing keypad however this is functioning fine after testing each of the switches. The real issue is the result of a leaking supercapacitor. The function of this capacitor is to retain data in RAM when the machine is off, and ensure the time and date remains correct. This one isn’t behaving like a supercapacitor anymore, more like a super resistor being almost completely open circuit with no capacitance. During its final years it has leaked electrolyte over the PCB in turn damaging traces, vias and neighbouring components.
We have ordered some new capacitors and also replacement logic ICs which decode the keypad matrix data as the legs are all corroded. We are now cleaning the board and repairing the failed vias which connect the top of the board to the underside.
Once we are happy the repair is complete we will connect it to our Siemens PG and run a test program to ensure everything works.
If you have any concerns over your equipment why not let us visit site and offer free advice on critical assets? There isn’t much we haven’t seen and simply opening a panel door can usually be enough for us to put together a plan of high risk equipment.
