Dear all,
First time poster here. We have two CNC lathes, identical, one of them is acting up. We traced the issues to the DC regulator of the main spindle drive, namely the 5V DC supply for the CPU control board. It has a strange dip (see attached trace). If that dip goes under 4.7V (and it does if the 230V supply line is under 226V), the board resets. The other lathe's 5V DC is clean, straight stable 5.0V DC.
It is a regular non-switching 5V power supply.
Is there a clean culprit for this pattern? The big electrolytic DC filter caps (still the originals from 1988)? The rectifying diode bridge? The 5V DC voltage regulator itself?
Best regards,
Mihaly