Last night there was some work being done to the power for our building and the backup batteries also ran out. When the power got restored, the system came up but gives no dial tone. It's a 1-stack, 3-PIM 2400IPX with dual CPU and dual TSW system.

Error messages say 1-A - Both TSW Failure (Permanent).

The CMOD command shows both TSW system in make-busy state. SINZ didn't help and complete power-down and power-up didn't help. I swapped the 2 SW10 cards with each other, but that didn't help eaither.

I got the Dterms powering on, and they all appear to be normal, but no dial-tone; obviously.

It's early hours, so my dealer is not yet reachable. Soon will be, but I'm looking for any help/advice I can get.

I would power down & do a fresh power up.

I did a complete power down. One thing about that is when the powerr got restored, every part of the system gets power, all at the same time. Yet, there is a very specific way to power down / up a 2400. I only have the manual for an 8500. What is the procedure to power this thing down and up?

We got the system up. I don't know if it's becasue we just tried to turn it on for the nth time, or becasue we did it differently. This time, we kept the power switch for CPU 0 off, before applying power to the bottom shelf (processor rack). Soon after, the system came up and got dial-tone. This is where we stand right now.
We are verifying operation of different functions and then have to check what recent MAT changes were not backed up before we lost power. Then we will turn CPU 0 back on and see if we can switch to that. Take it from there...

The general rule for IPX power-down / Power up is that the processor should never know that any other shelves went down. Processor is first-off last-on.

You can power-down/power-up a suspect card by using the port-micro switch on that specific card, without dropping the entire system. This will allow you to power off an remove a suspect card to see if it is locking up the system.

Hope that's helpful.

OK, here is more information on this.
If the system comes up on CPU 0, it works and with CMOD, you can switch the TSW system from 0 to 1 and they both work. When you boot the system on CPU 1, it says both TSW 0/1 systems are in make-busy, unusable and you can't use the system.
Also, if you boot up on CPU0, and everything works, and you turn on CPU 1, and then try to CMOD from CPU 0 to CPU 1, the system will again say (under the command of CPU 1) that TSW0/1 are both make-busy, unusable.
Then we tried to switch the CPU cables around, and the problem remained exactly the same: system works under CPU0 but doesn't work under CPU1.
While I possibly have a dead CPU1, would it worth a try to re-format the HDD of side 1, reload system software and programming data and try again on CPU 1? Or does the system keep those HDD-s on side 0 and 1 synced? Or any other ideas?

If I recall -- I'm rusty as hell on IPX -- The system syncs the HDDs as RAID 0 (identical copies). So if one HDD is failing, it might do what you're seeing. You should also see errors that the system can't sync the HDDs.

Like I said, rusty as hell on IPX... Formatting the HDD, or replacing the HDD would probably be my best guess for a solution. It does need to be an NEC HDD, according to old Georg the trainer out of Santa Clara, back in the day.

to correctly power down a NEC PBX... go to the last PIM and turn both power supplies off, then the PIM below it, all the way until you get to the CPU's.

To correctly power up a NEC PBX... go to the CPU's and power both power supplies on, then the PIM above, all the way until you get to the last PIM.

Processor is LAST-Off and FIRST-ON.

Richard Baker Tech ID 1095