Does anybody know a good tutorial, manual or where to start if I want to repair Cisco switches?? especially 3550 which I have two and the have failed..
Possible surge or dirty phase coming back in could have fried the power supplies, psu fan, or bridge rectifier (4 diodes). You can measure the voltage drop on the diodes (any diode you see, usually a tiny black cylinder with a silver stripe on one end) by putting a multimeter set to Ohms (upside-down horseshoe), and put the negative lead (black) on the striped side and red (positive) on the other side. Should get around .606
Also, take the connector off of the power supply and put the meter set to volts-dc (on the 20VDC scale) and put the negative lead on the black wire of the connector and the positive lead on the yellow, with the switch plugged in. Should get 12VDC. Then the positive on the red and negative still on the black---should get 5VDC.
Or, let me know if you want to sell them if you can't fix them.
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