APC AP7900 - Constant & Fast relay clicking (Engineers?)

[Anonymous user]

I have in my home lab a AP7901 that has a relay on the board (where the capacitors are, closest to the network management board) when plugged in, immediately starts clicking/shunting continuously at a very fast rate.  i would replace it if it were at work and not out of my personal budget, but this is my home lab and a luxury to have this item.  when the ribbon cable is unplugged, the clicking stops, and i am trying to understand what would cause this sort of thing to occur.  the network card also stopped working and i was wondering if it is perhaps bad firmware (the console cable still works).

i am handy and thing this is something that i can fix if it is a matter of changing a capacitor or resistor, i don't want to have to replace the unit as i'm not sure that i will be able to.

Many Thanks to all that can add anything to my issue.

[BillP]

That is from the end of 2005 so it is several years old.

It sounds like when you don't see anything under Device Manager, that communication is list. What firmware version is on the PDU?

[Anonymous user]

American Power Conversion               Network Management Card AOS      v2.6.4
(c) Copyright 2004 All Rights Reserved  Rack PDU APP                     v2.6.5
-------------------------------------------------------------------------------
Name      : RackPDU                                   Date : 08/07/2013
Contact   : Unknown                                   Time : 14:52:16
Location  : Unknown                                   User : Administrator
Up Time   : 0 Days 0 Hours 1 Minute                   Stat : P+ N? A+

Switched Rack PDU: Communication Lost

[Anonymous user]

It really isn't stable enough to update the firmware.  Do you have a feel for how much out of warranty service would cost?  Are there any known hardware faults?

[BillP]

We don't repair these unless there is another repair service out there willing to do it. The design life time of these is about six years so you are a little past that now.

The device can be in the state you've showed me to do the upgrade as long as network access is available.

[BillP]

Ok, so that is really old. The one free option I could suggest is that we update it (if interested), to see if it helps at all. I am not sure it will but that firmware is very old so I figure it is worth a shot for the unit if you'd like to try.

Let me know and I could point you towards the firmware and instructions to complete it.

[Anonymous user]

I have in my home lab a AP7901 that has a relay on the board (where the capacitors are, closest to the network management board) when plugged in, immediately starts clicking/shunting continuously at a very fast rate.  i would replace it if it were at work and not out of my personal budget, but this is my home lab and a luxury to have this item.  when the ribbon cable is unplugged, the clicking stops, and i am trying to understand what would cause this sort of thing to occur.  the network card also stopped working and i was wondering if it is perhaps bad firmware (the console cable still works).

i am handy and thing this is something that i can fix if it is a matter of changing a capacitor or resistor, i don't want to have to replace the unit as i'm not sure that i will be able to.

Many Thanks to all that can add anything to my issue.

[BillP · Accepted solution]

Hello,

It sounds like the display board that is attached to the NMC is possibly faulty. How old is this device? (you can give me the first 6 characters in the serial number to help with that question.)

Removing the display turns off the relays so that is why it is stopping when you remove it. Is the device still accessible at any time when this happens - can we get log files from it? What LEDs do you see on the front display during all of this when the display is powered?