A noisy problem

I have this PLC that has an intermittent but persistent problem. The PLC is Keyence KV-3000. One time, the PLC had error that says "access window damage". But after the error was reset via its reset button, it has been cleared.
After a few days, another error has appeared. This time it was an unknown error. We did the same thing & it worked like the first.
Then just yesterday, another error appeared. This time it is a memory card error, which is quiet absurd as there was no memory card used. Again, we did what we do before & the PLC worked again.
My questions are:
1.) The panel do not have a fan. Can the heat have effect on the PLC, especially it is summer? The panel is located in open air.
2.) Is it possibly a noise problem? How can I check if it is?
3.) I have installed a noise filter, is it possibly damaged? How ill I know if it is good or not?

Check the temperature of the panel it should be less than 50°C.
Check also the power supply and the grounding.

tarik1978 said:

Check the temperature of the panel it should be less than 50°C.
Check also the power supply and the grounding.

Click to expand...

We have already changed the power supply, because that was our initial assessment.

1.) Buy a hand held pyrometer and measure the temperature inside the cabinet at the end of a hot day. It should be less than the maximum operating temperature of your PLC according to its data sheet. If it is higher, add a fan.
2.) Yes. As a handy guide, checkout Rockwell's Industrial Automation Wiring and Grounding Guidelines, or the appropriate directives for your country. Also buy an oscilloscope rated for 1000V and oscilloscope everything and marvel at the noise. Use short probes.
3.) What kind of noise filter?