Cincinnati Arrow door lock stays locked, need help

Hello,
I've been running the Arrow 1000 for few years and last week while face milling an aluminum part it popped out of the vise and craw-bared the spindle. Lucky the drive belts were the weak point and except for the face mill damage everything survived.
However, now I have an issue with the door interlock. It stays closed and I have to manually open it with the manual override on the switch box to run a program.
When the spindle crashed there was an overload alarm from the spindle drive. After the belts replacement, the machine homes and runs programs but the door interlock stays closed. I also noticed that there is no relay click every time the axis is manually moved with the buttons that used to happen before. It feels like some sort of "ready" signal is not getting somewhere.
I had intermittent door lock issue before but it gone away after the EPROM battery on the RT board died and had to be reflashed. I'll try reseating all the control boards but suspecting that the problem is somewhere else and maybe related to the drives somehow. I tried reloading drive parameters but no change.

Looking for suggestions.

Thank you.

Got it fixed. Turned out to be a failed optocoupler on a relay driving the door interlock circuit (CR26). It is a socketed DIP-8 part, just pull it out, put a new one in and all is good.
Funny thing is that I fixed this same exact issue before by replacing this part . It all started getting back to me once I got into it.

Interesting
Would not think an optocoupler would be a failure point
Someone in the future is thanking you for posting this update

You should check the wiring. Something is probably causing a voltage spike that is killing the optocoupler. It should last forever if the voltage stays in spec.

Yea, I'm not sure what is causing the failures, the wiring seems to be in good order, maybe excessive ripple on the powersupply. Had another one die couple days later. This one controlled the tool release air valve. At least it is easy to diagnose since there is an LED next to the optocoupler that lights up when the control send the signal.