Peaks in spectrum / reason?

Hello. Recently we had an issue that the spectrometer would spontaneously shut down. Afterwards it would try to restart but could not finish initialization. Then it would start over again. We found that the instruments starts up correctly, when disconnected from the PC (network cable). So we exchanged the cable and it works again. But since then we have spikes / peaks in the spectrum especially at 500cm-1 but also At 1000, 1500 etc. The service tells me, that it might be the power supply. Maybe anyone of you has experienced this before? Thanks for any sort of advice. Best regards. Michael

Equipment: PerkinElmer - Frontier FTIR