WS-26-500-DC Powers up, shuts off after 5-10 seconds

[Dawizman]

I'm out at a tower site that's down. If I pull the fuse powering the switch, and plug it back it after 10 seconds, my switch will power up. Within 5-10 seconds of powering up, it shuts down. The switch is running 1.4.7rc22. Could this be related to a hibernate voltage setting? My batteries are 10v higher than the configured hibernate voltage though. Either way, I've got a replacement installed right now, just upgrading to 1.4.8rc4.

[Julian]

So order of events is:

1: apply power
2: switch boots after short delay
3: few seconds go by
4: switch shuts down? <- are you sure it wasn't a reboot?
5: pull power? <-- how soon?

Not leaning toward hibernate settings at this point,

[Dawizman]

That's exactly right. Power led and fans all shut off. I waited about a minute before pulling power and trying again.

[Julian]

Strange, very strange. with the earliest revision of bootloader (which you have no way of checking) there was some unexpected operation in the form of a reboot after loading power supply app.

this is a new one on me. If you can get the power supply to the board stable, a firmware upgrade could be the ticket, IF the behavior is the power supply app, and not the bootloader, I am hesitant to call hardware on this, my prototype (not even a release version) has so far been absolutely bulletproof. *knocks on wood*

if you had a bench power supply and a console cable, i'd bet a pastebin of the rs232 output would be helpful in diagnosing root cause, but the long and the short of this thread is probably going to be 'send it in, i'll get you handled'.

Powering from bench 12-48v, do you have identical behavior?

[Dawizman]

I'll get it on the bench after lunch. From what I understand from a previous discussion with Chris, this switch has an older version of the bootloader which had a bug that you found after the initial 15 pre-release units were shipped (which I received 5 of). I don't mind doing some troubleshooting here with you before shipping it off though.

[sirhc]

I'll get it on the bench after lunch. From what I understand from a previous discussion with Chris, this switch has an older version of the bootloader which had a bug that you found after the initial 15 pre-release units were shipped (which I received 5 of). I don't mind doing some troubleshooting here with you before shipping it off though.

This is why we did a small "pre-release" as a shake down run and we discovered this issue and changed it before we ran production which we are still waiting on those units.

The bug "if you want to call it that" does not cause this behavior.

All the "bug" does is when you do a firmware upgrade "IF" there is also a new power supply APP distributed in the firmware it will cause the switch to power cycle.

We do not upgrade the power supply APP very often (like rarely) so after upgrading to v1.4.7 or newer this would only occur if we change the power supply APP which as I said is "very rare".