My Fluke LinkRunner has a fault...

[chazzy2501]

The trusty linkrunner I acquired from the old boss many years ago now shows intermittent cable faults that don't exist. 

 

The new ones are sooo expensive!  I have an even older one that still works perfect but she's hefty and can't just sit in the tool box. 

 

So is there a non-fluke tester that is worth anything? 

 

The current one is the size of a walkie talkie, can do dhcp, ping and show cable lengths for every pin. (super duper handy), send a tone with an 3rd party sniffer and it can check cables. (1" mono lcd job, not touch screen) 

 

Also it uses AA batteries can be left for months and just work!

[synaesthesia]

Sure it's not just the RJ45 port going flakey with age?

If you're handy with an iron, replacing it shouldn't be too much of a faff.

[chazzy2501]

1 minute ago, synaesthesia said:

Sure it's not just the RJ45 port going flakey with age?

If you're handy with an iron, replacing it shouldn't be too much of a faff.

This is probably the exact fault but no, I'm a soldering hack and my eyes suck and the tools are subpar.

[Chris_Cook]

I'd maybe try some de-oxit, contact cleaner or IPA to clean the sockets. Otherwise, if you can find a local TV/Electronics repair person, or amature radio operator, the might be able to resolder the connector. If its just a dry joint, it shouldn't be too difficult to re-solder it with a decent soldering iron.

[Andrew_C]

Have you got a science technician...?

[dmj]

3 hours ago, Chris_Cook said:

 

If its just a dry joint, it shouldn't be too difficult to re-solder it with a decent soldering iron.

If its just a dry joint, I found that reflowing them in an oven can work quite well. I recall we has some HP boards that suffered from dry joint issues. We'd strip anything melty off the board, add some flux then commandeer a cooker from food tech, whack it up to max and leave it in there 20min. Worked a charm. YMMV.

[southhamster]

A company providing electronic test gear calibration services might be able to help with repairs, at least with Fluke it's expensive enough to make it worthwhile!

[Davit2005]

Most devices these days have surface mount components a normal soldering iron is not really suitable.

 

Jus to show you some of the techniques I watched this the other day on YouTube, funny enough featuring a Unifi PoE Switch with faulty ports.

 

Of course the usual warnings when repairing electrical equipment should be observed, if playing with live equipment make sure you follow precautions if unsure leave it to a professional 🙂 

 

https://www.youtube.com/watch?v=ZGkLkHcSZ3U

Edited Saturday at 08:43 by Davit2005

[synaesthesia]

Hot air soldering for network ports works well (ish) - I've never managed it without mullering the plastic even with copious amounts of kapton tape. Not tried a Fluke yet though, but have done my cheap and cheerful tester at home twice (second time to replace for a non-chinesium rj45 port which only lasted 10 minutes!)

WIth network ports if it isn't oxidation it's generally because the metal is low quality or more likely in a Fluke, metal fatigue due to age so the pins no longer spring up and make full contact with the connector.

Edited 7 hours ago by synaesthesia

[Andrew_C]

On 18/09/2026 at 21:44, southhamster said:

A company providing electronic test gear calibration services might be able to help with repairs, at least with Fluke it's expensive enough to make it worthwhile!

Fluke PAT box - 1200 new - 700 for a new screen.

[Fazza]

I'd have a go at cleaning the ports with some Contact Cleaner and a toothbrush first and then look for dry joints on the ports inside. If there are any dry joints then all you need is a soldering iron to reflow the solder.

 

If it doesn't work and you're looking at replacing it then why not just have a go at repairing it yourself, if it still doesn't work after you've had a go then you're still in the same boat where you will be replacing it but by attempting a repair you might just get lucky and fix it!

[chazzy2501]

ok, I took it apart used magnifying glasses but the solder joints all looks good.  I looked in the socket and 2 of the pins looked lower than the rest..  I ended up stripping a sandwich tie and making a tiny hook, slid it under the pins and pulled them forward. by the time the hook quit the pin was at a similar level to the others.   

 

it appears to work well with wiggling the rj45 around.. So is it failing or did something get in the socket at one point.. I guess I'll have to wait and see.

 

Also every external screw did nothing, the years of dropping means they're all broken and a single screw holds the unit together... Now lots of tape and a single screw.

 

 

[Fazza]

Wiggling for me is a sign of a dry joint - you dont need to do much more than hold a soldering iron on each soldered pin, wait for the solder to melt and then promptly remove the soldering iron - this will ensure the solder is reflowed and a proper connection is made.

 

Then try wiggling it and if it still happens then you may need to replace the ethernet port, a fairly easy thing to try or certainly something most electronic repair companies can do.  Companies that calibrate test equipment should be able to do that for you for well under £100 which is so much cheaper than buying new kit.