3550 on its lasts legs

I have to switch it on/off several times to get it to boot. Once up, it is fine unless I turn it off.

If it's off for a while, I have to turn it on and leave it on for an hour until it "warms up". Then I can shut it off and back on and I can go through the whole shut off/turn on thing until it boots OK.

Does it sound like a power supply? I can get one for $90 but I hate to throw good money after bad.

Any opinions would be appreciated.

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Comments

tiersten

You got any volt meter you can measure the output of the PSU with?

I generally don't do very much diagnosis of faults with network gear because its either a dead card or a dead chassis and in either case, it just gets replaced.

Netwurk

Yeah, I got a meter. Maybe it would tell me something if the voltage changes as it warms up. Would love to know what the voltages are supposed to be, with or without a load. But that kind of info isn't easy to find.

creamy_stew

Certainly sounds like a bad capacitor somewhere. I'd guess on the mainboard, as that is where those seem to fry on computers. Never had this problem with a cisco switch though. Buy a 3560 on ebay? (or a 2960 if you don't need routing) 2960's now support DAI and IP source guard. So if you're using it for those features get a 2960 and throw in a smartnet.

Netwurk

I'm considering getting an RPS300 as it goes for about the same as a power supply and will work with a lot of different model switches.

EDIT - scratch that idea

"RPS 300 supports all Catalyst 3550 Switches except the Catalyst 3550-24 PWR"

DPG

I have had the power supply go bad on about 7 different 3550-24-PWR's. Must be a common problem.

Usually they will start to take a while to power on when plugged in. Later, the led's would flicker as though they weren't getting enough power. Finally they wouldn't power on at all.

Netwurk

DPG wrote: »

I have had the power supply go bad on about 7 different 3550-24-PWR's. Must be a common problem.

Usually they will start to take a while to power on when plugged in. Later, the led's would flicker as though they weren't getting enough power. Finally they wouldn't power on at all.

That is exactly the symptoms I'm experiencing! I think I'll be ordering a PS

Many thanks for the info

Netwurk

Took a while to find a good deal, but I got a PS for $90 and my 3550 is up and running again.

Thanks again to DGP - without his advice I would not have been able to narrow the problem down to the power supply.

DPG

Netwurk wrote: »

Took a while to find a good deal, but I got a PS for $90 and my 3550 is up and running again.

Thanks again to DGP - without his advice I would not have been able to narrow the problem down to the power supply.

Did you order it from the Chinese seller on eBay? I need to order 3.

Netwurk

DPG wrote: »

Did you order it from the Chinese seller on eBay? I need to order 3.

Seller was 802.1net - it was missing the metal cover which might also act as a heat sink. Doesn't seem to be running hot, but it might be an issue if you use these at work.

Here's a snippet of the tracking, it looks Chinese to me

CINCINNATI HUB - USA CINCINNATI HUB, OH - USA
HONG KONG - HONG KONG HONG KONG - HONG KONG
SHENZHEN - CHINA, PEOPLES REPUBLIC SHENZHEN - CHINA, PEOPLES REPUBLIC
GUANGZHOU - CHINA, PEOPLES REPUBLIC

tiersten

Can you take the cover off the old one and put it onto the new one? Only do this if you're aware of the dangers of electricity and won't do anything daft when swapping it over :P

Does the insides of the PSU look similar to the old one? If its significantly smaller then it might be a "Chisco" brand PSU and not actually be up to rating.

Netwurk

tiersten wrote: »

Can you take the cover off the old one and put it onto the new one? Only do this if you're aware of the dangers of electricity and won't do anything daft when swapping it over :P

Does the insides of the PSU look similar to the old one? If its significantly smaller then it might be a "Chisco" brand PSU and not actually be up to rating.

I once did power supply repair for a living, so I'm not likely to get zapped.

The old cover is welded on, so I decided against reusing it. I previously took it off the old one (no easy task) to see if I could spot any popped capacitors that I could replace. No such luck.

It may be that the purpose of the cover was to prevent shock to techs who have the lid open. Some PS components hold a charge even after you unplug them.

It looks exactly like the other PS other than the cover. So I doubt it's a Chisco. It has the Cisco part number on it and claims to be a 341-0029-03. That makes it newer than the 341-0029-01 it is replacing and I'm hoping it's the -01's that go bad.

The IOS recognized it in the show version, so that's a good sign. A better sign is that's working and providing power to my IP phones.

tiersten

Netwurk wrote: »

I once did power supply repair for a living, so I'm not likely to get zapped.

Ahh okay. Gotta give the warning just in case though! Don't want somebody thinking it was completely safe to poke around in there

Netwurk wrote: »

The old cover is welded on, so I decided against reusing it. I previously took it off the old one (no easy task) to see if I could spot any popped capacitors that I could replace. No such luck.

It may be that the purpose of the cover was to prevent shock to techs who have the lid open. Some PS components hold a charge even after you unplug them.

I don't think the cover is necessary for cooling. Some of the other fixed config Cisco switches I've taken apart have had a bare PSU PCB bolted to the case. I think its just whoever manufactures that particular PSU for Cisco and whether it is a user replaceable part or not.

Netwurk wrote: »

It looks exactly like the other PS other than the cover. So I doubt it's a Chisco. It has the Cisco part number on it and claims to be a 341-0029-03. That makes it newer than the 341-0029-01 it is replacing and I'm hoping it's the -01's that go bad.

The IOS recognized it in the show version, so that's a good sign. A better sign is that's working and providing power to my IP phones.

Ah good. Hopefully its more reliable than your old PSU!