3548XL Fan Operation

[Scott Pickles]

I have two 3548 XL switches that I bought from auction.  When I boot the switches, the fans do not spin up.  When I run them for about 10 minutes, everything seems to be fine other than the fact that they are getting hot.  I have removed the fans and tested the pins supplying voltage to the fans and they are fine.  I have tested the fans themselves with external power and they're ok too.  So is it normal for them to only turn the fan on as needed?  Most of my switches run their fans 24x7, so I'm curious about these switches and I'm afraid to put them into service for fear that they'll overheat and die.  Thoughts?

Regards,
Scott

[hobbe]

misread it and thought i answered another question.

Sorry

[glen.grant · Accepted solution]

  No they should run all the time when powered on .Seeing these were brought out in about 1995 timeframe its very possible the fans are shot at this point.

[Scott Pickles]

Glen -

That's what I figured.  I turned the board over and there's a blown cap right on the primary circuit to the fan.  I'll solder in a new one and should be all set.  Tested the fan with an external power supply and it was bad too - turned out to be a loose/broken wire.  Resoldered that as well and the fan now works.  I just need to fix the circuit board.  I got 4 of these on public auction for $10 each, so I'm more than happy to deal with fixing them!!

Regards,
Scott

[Leo Laohoo]

Hey Scott,

Haven't seen you for awhile.  How's the holidays?

Do you have another 2900XL or 3500XL that you can use as a "Christmas Tree"?  (It means that this until will give away parts.)

The 2900/3500 can take some punishments.  We had a few with dead fans and we didn't know until we had visual inspections.  One way for the heat not to accumulate is to remove the lid and install the switch standing on it's side.

[Scott Pickles]

Leo -

Thanks for the response!  The holidays were crazy, and I pulled a lot of late nights upgrading the network during the 00.001% of the year we all have for network upgrades.  I haven't been around since the birth of my second son back in October.  Add to that the two hospitals I'm managing for VoIP surveys and I'm a bit busy.  As for the 3500XL, turns out it's a popped cap near the power relay for the fan.  I'm going to take a switch from my scrap and desolder a cap to use to fix it.

Regards,
Scott

[Leo Laohoo]

Congratulations to the new addition to your family.