Teach Pendant Messages ... I need advice regarding them.

There can be several estops. Message is specifically stating external one so yes, you need to check the wiring if your safety is hardwired. The question mark is indicating operating mode. In thus case it us unknown. Mode circuit is also wired to same board as safety signals (estop etc). So if this board is not powered or wired correctly, you will see what your screenshot shows

yes...

correct wiring depends on controller variant. just check your robot documentation or search forum.

here is what i used for KRC2 controllers

You can test if its the estop on the front by taking it out and bridge it FOR TESTING ONLY.
Replace it anyway, becouse its a safety item.
Check the connections on the ESC board if they are correct.

Quote from bakerhesseldenz

Based on that diagram, my X11 plug looks like it is wired correctly. Could there be a problem with the emergency stop that is located on the front of the controller? The controller was slightly damaged during shipping ... the top of the emergency stop switch was broken off

Unlikely -- the internal and external E-Stops have separate messages.

The fact that you have both the internal and external E-Stop messages, as well as Unkown Operation Mode (scroll up the message window), indicates that the safety board is not receiving power.

If you stand in front of the cabinet, its the pcb on the right side.

Quote from bakerhesseldenz

Which board is the safety board? Is it inside the PC, or inside the main controller box?

Depends on what generation and model KRC you have. KRC2s came in a few varieties, with the biggest divide being between the ed2005 models and the pre-2005 models.

For an ed2005, the safety board is the ESC board, located in the bottom right of the main cabinet. It's a solid-state PCB. If you look carefully (involves sticking your head into the cabinet), there's a small blue block on the board with a small black button sticking out of it. This button resets the board in the event of a single-channel fault.

For older KRC2s, there are a variety of safety boards, but in general they're all large, with large transparent-housing relays, and labelled FE20-something. The old safety boards were often easier to diagnose, since each relay had associated LEDs that showed their status, and the KRC wiring diagram included all the details of how the relays interlocked.

Read schematics. As i recall all four are used. You should measure 24V (or 27V) across two pairs of contacts

Then you are mistaken.

Forum is place to ask for help and get a hint that points you in the right direction, so you can solve some issue yourself - in a field you are familiar with. It is not a substitute for formal training. Nobody is going to compress into few sentences what normally takes years to learn. I would recommend hiring someone that does this fir living.

In case you insist on doing this yourself, you need to at least learn some fundamentals. For thato you can check youtube videos such as dc circuits, how to use multimeter, how to read schematics etc.

Details matter. Just grabbing a semi-random connector with a fuzzy photo gives us nothing to work with. That relay layout doesn't completely match any board I'm familiar with, so I can't make good guesses from that.

What is the label on the board? What is the label on that cable? What is the actual version of this KRC? Do you have the schematic drawings for this particular KRC? There were a large number of variants, and the connectors and pinouts changed. Are there more boards with similar relays elsewhere in the cabinet?

This, for example, is what a typical CI3 board looks like:

I'm sure you can see the family resemblance, but also multiple differences. None of the CI3 boards I did a quick lookup on in my archives looks like yours. Without something like an actual part number for that board, my only hope of finding a match would be to trawl through my archives looking at every photo. And I have over 100GB of archives. Supporting the forum is something I do in my spare time. Do you understand why the people trying to help you are getting a bit annoyed?

Quote from bakerhesseldenz

OK. Sorry about that. My post and follow up comments did answer all that though. I apologize for wasting everyones time.

No... you still didn't identify the board model number, or the KRC version (I can guess that it's a ed2005, given that it has what looks like a Ci3/ESC board), or the relay states, or the status LEDs on the board.

The attached PDFs have the closest matches (not perfect) to what you've shown. They include the details on which connectors, relays, and fuses on the board are part of which safety circuit. Hopefully they'll help some.

that is the safety board. so circuits are redundant. this means that any of the safety signal has two channels (A and B). and both MUST be switched on/off simultaneously. the tolerance window is tiny (milliseconds). re-applying power can be seen as 'sync'. this is what blue button on the lower right corner is for. it allows quick reset without much longer reboot. all safety inputs need to be wired and they are dual channel. and wiring need to be correct. cross channel faults or single channel mistakes will cause a trip. some trips are easy to recover from, others trigger lockout. so having that blue button is a lifesaver.

Quote from bakerhesseldenz

but when I plugged it back in the ESC board made a click sound. Following that, the red blinking lights went away on the servo drives, and the teach pendant was now allowing me to do more. I still can't jog the robot ... but I do think that has something to do with the Operating Mode switch on the front of the controller ... or the wiring to and from it. The pendant still is not recognizing the mode the switch is in ... Just shows a "?" where "T1" should be.

That suggests that the ESC board is actually working. It's been a looong time, but IIRC, in this situation, if you hit the KCP E-Stop, you should still get a separate E-Stop message, and be able to clear it after releasing the E-Stop. That would confirm that the ESC is working.

The servo drives throwing errors when the ESC is unplugged is normal -- the internal safety loop passes through the KPS, the KSDs, and the ESC (and the KCP, IIRC). So that resolving when you re-connect the ESC is further evidence that the ESC itself is probably okay.

The "external safety" part of the ESC board is powered through the external X11 connector. This gets tricky due to sub-variants, but in general, the end user had the option to provide safety power from an external source, or power the safeties using the KRC's internal power. So the "input power" pins on the X11 need to have 24-27VDC applied. The most common approach is to put jumpers inside the X11 hood, or on a terminal strip in the remote panel the X11 connects to, to feed the X11 24VDC "output power" back to the "input power".

Each operating mode (T1, T2, AUT, EXT) is "engaged" by closing a specific pair of relays on the ESC. Each pair is wired to the Mode Select key switch. If there is no external power to the ESC, none of the relays close, creating the "Unknown Operating Mode" condition. Also the External E-Stop condition, since that's a "fail safe" circuit -- a loss of power, a cut cable, etc, are treated as if the EEStop was hit.

In the image below, that would be pins 28-30, and 29-31. However, that image is from an ed2005 KRC2, so those pin numbers may not apply to your controller. So approach with caution. Most of the ESC board is well-protected, but the power connectors are the ones most likely to let the magic smoke escape. And finding spare parts for a KRC that old isn't easy these days.