Hurco - KMB1 Before I start

I recently acquired this 1.7HP spindled UK spec 1980 Hurco KMB1 that’s been unused in a dry workshop since 2001.
Its condition is like new, and all the electrical cabinets seem untouched from the day it was built, to me at least.
Before I update it, I would at least like to see it run.
The machine has air and three phase power and a master tape that works, well it runs through to the end and gives me the language choice, but after the power button doesn’t latch the COR relay.
Emergency Stop String
here, some fine person has posted what I had hoped would be the answer.
I have traced the 24 volts from TB3-1 past the power switch to TB3-2 beyond the emergency stop switch and low air pressure switch to TB3-21 at the coil of the COR relay. It is also present on the other side of the COR relay on TB3-18/Interface J3-2.

I thought that when the Master tape runs, the Pin J3-2 would go low and enable the COR relay to remain latched, but this isn’t happening, so I guess the Control or Interface is not happy.

Can anyone throw out some straws I could clutch at please?
Thanks

Look at all the voltages from the power supplies. Old capacitors are often the problem.
Look at the ripple on the supply.

Thanks,
The 5 volts are at around 4.8/4.9/5.1/-4.8 depending which regulator you check.
The 15v are at 15.1/14.4/-14.4
The 25v is at 24.9
I looked at each with a scope, and seems a straight line with DC coupling, with AC coupling, each has some minor high frequency noise at 50mV max. No sign of any 50Hz ripple.
Sadly...

I don't have a KMB1 but I would check the limit switches.
On my mill the roller limits were gummed up and could get stuck in the tripped position. I assume the limits are tied into the estop circuit to kill power to the drives.

This machine has magnetic sensors for limit switches, so cannot gum, but I will check those out.
Oddly, if I press the e stop, that does register on the screen, so no idea how its detecting that.
Thanks.

I did find that the Y axis was hard up against the column, so have manually wound it out a couple of inches, but have been unable to test since the tape drive has quit.
Not completely. It winds back to the start when you tell it to reread the tape, but when the beginning is reached, it won't start driving forwards and therefore read anything. I've continuity checked the drive motor, but other than that I've no idea what might be the issue now.

Thanks,
No I looked at the belts and truly impressed by how taught and in good condition they are.
No it’s the version prior to serial port introduction.

Just for the record, I never did get the tape to consistently run. Bought a tape emulator from Buddy Maughon at Accurate Machine Tool Serv. Initial issue was some of the 5volt regulators were marginal, so I replaced them all with PSU5 LM323 replacements from ezsbc.shop/.
I had also to replace a number of chips on several of the boards, eg watchdog timer, x axis counter, y axis encoder as the scale had a chip out of it and counted incorrectly, relay optical isolators, then all the tantalum caps on the 2 parajust control boards to get the spindle to run, but in the end, it works accurately as an original Machine and still does. But now started to Linuxcnc it in a sympathetic way.