Our (very) old 7400 has decided to throw a tantrum in it's last months before it's replaced! Always going to be the way.

Analogue and digital extensions are working; IP phones are not. They have been, without issue, for a considerable period of time, years. I joined the organisation 3 months ago and they were fine. Then last week, all IP phones when dialing, or when dialed from a non-IP phone in the system, started displaying the 'No MGI Chs available' error.
We started by disconnecting and reconnecting the network cable. That worked, second time around, but was only a temporary resolution. It was fine for several hours, beyond the end of the day, but failed again over the weekend.
Network switch port was configured to Auto/Auto, now configured to 100FDX.

Module installed is an OAS in Cab 1 Slot 11, as shown correctly in Cabinet Information. This (I think) incorporates a 'MGI Base' providing 16 IP extensions (also shows as C1 S11). Service selected is 'MGI-16 ONLY'. OAS shows to have 64 channels, all are 'Idle', and show as 'Make Busy'...? (I know what this means on a Mitel system, and would RTS but don't know how to do that on the 7400.)

I was (once upon a time) Mitel and Nortel certified but have never had the joy of working with a Samsung unit. My gut tells me the OAS has decided to call it a day, but is there anything further I can do to verify that?

Any further info I can provide?

Please HELP!!!

The oas cars is the issue. Try restarting it.
The mp40 (processor) take to the oas via the lan.
Can you ping the oas card?

I can ping the OAS card; I can telnet to and log in to the OAS card.
Is there a simple format or command for restarting it?

It's running v2.05 software which while not the latest, has worked up until now.

Apologies - there is (of course!) a simple way to reset the card - poke something into the reset hole on the front.

This appears to have again got things working. Let's see how long it lasts this time!

Thanks.