If the long run is working as are short ones then it suggests the actual wiring itself is probably OK. Two possibilities - dodgy patch cables (I have had a few over the years) or sockets where the contacts are not down far enough.
With the patch panel end connected to the switch and the other connected to the PC, are any of the LEDs on the PC RJ45 socket illuminated?
Are you sure that you are testing a cable that is connected to the switch? You could have some idents swapped round. Yes, another silly suggestion, however it does happen.
2 Patch panels and 58 connected ! What size panels are they?
M H C
taurus excreta cerebrum vincit
Edited by MHC (Wed 11-Feb-15 08:44:55)