We have 3 Parker 890 drives (Model: 890SD-532450D0-B00-1A000) installed in one of our machines. Every year at least one of these three drives fail with HOT fault. The fault doesn't get reset even if the drive is in off condition for months. Once the drive fails with HOT fault, the heat sink temperature in drive's display starts showing constant 125°C, even if the ambient temperature of the panel remains between 28-32°C and there is enough gap between all three drives.
For repairing the drive we replaced old PCB (AH500819U001/1 AH500819T011/1) by installing newly purchased PCB (AH500819U001 04). But after installing new PCB the drive starts tripping with fault "INCOMPATIBLE STO TEST RECORD".
Please suggest why our drives are regularly failing with "HOT" fault. And also suggest the part no. of spares or PCBs to be replaced in order to repair the drive.