3 POE switches for repair

[smason]

Just got 2 8 port Gigabit switches, and a Cisco 3550 25 port 100MB POE switch for a song.

The big Cisco has an SMPS problem, the classic chirp chirp chirp when you plug it in. Had a quick peek, it's a Liteon SMPS looks like it's built like a tank. Will disassemble it when I get some time.

The 2 9 ports have no power supplies, so hopefully that's all that is wrong with them. Unfortunately they need 48V 3A supplies, a bit less than standard.
Have to kludge something together for testing. My bench supply only goes to 24v. I won't need 3A to test, 3A is for supplying POE for 8 devices.

More to come

[retiredcaps]

Re: 3 POE switches for repair

The big Cisco has an SMPS problem, the classic chirp chirp chirp when you plug it in. Had a quick peek, it's a Liteon SMPS looks like it's built like a tank. Will disassemble it when I get some time.

I would love to see pictures of Cisco internals.

A lot of companies run these switches 24x7 obviously and depending on where they are installed, the caps could on their last legs due to long run time and are near their stated lifetime.

I have seen switches stuffed inside closets with no AC and it can easily be 35 to 40C air temperature and even hotter inside the chassis.

I think the 3550 series was 2002-2003 era. So it is possible they have been running nearly 10 years non stop? Close to 87,000 hours.

[smason]

Re: 3 POE switches for repair

I would love to see pictures of Cisco internals.



I think the 3550 series was 2002-2003 era. So it is possible they have been running nearly 10 years non stop? Close to 87,000 hours.

Will post photos when I get at fixing it, probably in a few weeks.
You're right, sounds like you know your Cisco gear. The manufactured date sticker I think said 2003.

I've been guilty of installing switches in unventilated wiring closets myself, somtimes there's no choice. When we re-did our main floor I had them add ventilation in the wiring closet ceiling, and vents in the doors. Good thing, it's balooned to 5 switches, a phone system, voicemail server and backup appliance in there. I still had to add an oscillating fan pointing at the front of the rack to keep the temps in line.

[seanc]

Re: 3 POE switches for repair

The Catalyst 3500 series switches seem near enough bullet proof.

Across 2 sites I maintain there must be nearly 20 of them. Apart from fan failures which puts the orange light on, they seem to be running fine. These ones are manufactured between 2001-2002 and we are phasing them out.
Most are in server rooms or out buildings with temperatures that rise and fall with the weather.

Bear in mind that the Cisco 3500 series is not standard PoE, it is Cisco Inline Power, so as such will only likely power the 7900 series of phone.

[smason]

Re: 3 POE switches for repair

Bear in mind that the Cisco 3500 series is not standard PoE, it is Cisco Inline Power, so as such will only likely power the 7900 series of phone.

Crap! Won't be much use to me then. Thanks for the heads-up.

[seanc]

Re: 3 POE switches for repair

You can fool a standard PoE switch into turning on its 48v power for a Cisco inline power phone using a special pinout of ethernet cable and a resistor, it might be possible the other way round but I have no idea how.

Voip-info usually has most of the information, here's a link: http://www.voip-info.org/wiki/view/Cisco+POE