phadobas

I came in this morning, and I noticed a ticking noise from one of the PIMS (shelf). No, this is not the alarm... That would be a continuous regular ticking about 1-2 times per second.

This one is comiong from the PA-PW55 card (the power supply card), and sounds like it's just sending ringing voltage to an analog station. But it just won't stop ticking!

There are 4 analog line cards in that shelf, and I pulled all of them out. The ticking still occurs. The rest of the cards on this shelf are T1-s, Dterm cards or DRU cards. None of them needs the ringing relay from the PW card to do anything.

The ticking pattern is as follows:
- 4-6 seconds silence

- 15-18 seconds ticking period. In that period, there is a "tick-tick" (the ticks are separated by 1/2 second), and 2 seconds silence.

- then the 4-6 seconds silence follows again.

This same pattern repeats for about 3 hours now.

I did reset the PW card, (it has its redundant fellow sitting right next to it), and now this redundant (backup) card provides power to the shelf. I'm not able to tell which one of the two card makes this noise. I also noticed that when an analog line supposed to ring, the ticking actually comes from the line card, not from the power supply card as I thought before.

But this weird ticking is coming from the power supply card (at least it sounds like it), and I never had this before, and this siwtch had been in my office for the last 8 years so I'm pretty familiar with all its ticks.

Any thoughts from anybody?