I've reviewed the various Ethernet cable testing questions here and they don't address my particular issue.

I have this super cheapo tester: enter image description here

I've used it successfully with Cat5e cable and one 30' or so cat6 cable. Today I made an approximately 60' cat6 cable and the tester is flashing the LED for position #5. That's it, no sequence, just that one LED. Battery is measuring 9.65v

I've looked through the "manual" but there is nothing about this. I've also read a description of the product on Amazon which is helpful (so I will include it in this question for others) but doesn't address my situation:

Following are abnormal connections:

If one cable, for example cable NO.3 is open circuited, the two NO.3 lights of the main tester and remote tester will not turn on.

If several cables are not connected, several lights will not turn on respectively. If less than two cables are connected, none of the lights is on.

If two ends of a cable is disordered, for example NO. 2and NO. 4, then displays on:

Main tester: 1-2-3-4-5-6-7-8-G

Remote tester: 1-4-3-2-5-6-7-8-G

If two cables are short circuited, neither of the corresponding lights is on of the remote tester while main tester remains unchanged. If three cables, including three, are short circuited, none of the corresponding lights is on.

If test patch panels or wall plate outlles, two cables which can match each other (RJ45) will be connected to the tester.

If test cables of the same axes, BNC turns on when the cable works.

9V reduplicated battery is used in this tester. Battery is advised to change if any weak light appears.( Battery is not included.)

Does anyone know have experience with a similar tester and know what a single flashing line indicator LED means?

Update: I've just tested it with a 80' cat5e cable here at work and it's operating fine.

  • Which indicator is flashing? – Moab Nov 25 '19 at 22:22
  • Indicator LED #5 – Steve K Nov 26 '19 at 2:20
  • What does the user manual say #5 is? – Moab Nov 26 '19 at 5:08
  • 2
    It doesn't, but presumably it refers to wire #5. – Steve K Nov 26 '19 at 15:41
  • @SteveK just to clarify: is only LED #5 flashing on both the large and small modules? Or does the larger module illuminate LED #1-8 in sequence while the smaller receiver module only flashes LED #5? This question shouldn't have been voted to be closed as it's not a duplicate. It's an interesting and unique problem. – Mr Ethernet Nov 27 '19 at 2:07

It means Re-Crimp your cable.

I can't say for your cable tester, but I have an old Belkin tester that is very similar. On the Belkin it basically meant that there was no continuity except for the flashing pin. (It also flashed red for out of order pins)

You can probably verify this if you also have a digital multi meter (DMM) by taking a ohmic resistance reading of the pairs in question. It's usually easier to just re-crimp though honestly, but if you would like to, check the AWG gauge of the cable in question. Then look at the ft marking of each end of the cable and determine the approximate length. Now go on Google and look up a AWG chart and figure out what resistance per foot your cable is.

If the reading is showing an open circuit on any single wire, then the cable is bad.

If the DMM has a much higher ohmic reading than what the AWG chart predicted for the footage... The cable may have knotted or pinched at some point and be damaged.

Also, it may be rare but I have come across defective CAT-6 connectors where the gold pins inside the connectors were bent, not sharp enough to puncture into the shielding of individual wires, and all together absent. So, if you bought these at a Home Depot or the like in a pinch, do yourself a favor and order some more from a reputable source.

Hope this helps

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