text: <s>[INST] PF 753 No HIM Response We have a PF 753 that has over heated several times the past few weeks becasue the cabinet a/c unit quit working. I have not been able to power up the drive after the last incident. When power is cycled, the HIM starts to boot up but never makes it past the screen that says Allen Bradley when first turned on. Any ideas? [/INST] If you look at the status LED next to the HIM, it is most likely flashing orange, maybe in a repetitive code (x number of flashes, pause, repeat). I cannot find any documentation what the blink codes mean, but ANY orange blinking is not good. You can try removing and properly reseating the HIM, but most likely the main control board is dead and must be replaced. If you have multiple PF753 drives, you can try swapping in a known good one to be sure it is just the main control board. The part number for a replacement PF753 main control board is: SK-R1-MCB1-PF753 \\n </s>