I have 4 PC in 25 mtr distance each. I can try to connect by switch but network show connect and disconnenet

Check the CAT5. The Terminators (RJ45) could be the problem. Single out which one flickers in and out. Now, 4 PC @ 25 Mtr each...i think you mean in a STAR BUS network. Max for CAT5 is 100 mtr, so no problems there. Usually switches dont die out, since they dont work that hard...Routers work 2x as hard, but those dont die out much either. I'd single it out to a defective NIC or the CAT5 itself. Could be a break in the cable somewhere or the terminator.


This is where a tone generator is handy. Plus in the terminator to the tone generator and see where, if at all, the leak in the CAT is.





Good luck