[rlisin]

The easiest ways are

1. With a spare cable - open the headphone, connect the spare cable to the suspected driver's contacts (where the original cable is soldered to the driver), check if there's sound. If yes, the driver is OK, the cable is the problem.
2. With a DMM - open the headphone, connect the DMM probes to driver contacts (where the cable is soldered to the driver), test the driver (check resistance and/or continuity). Then connect the DMM probes to the cable on both ends (the plug and driver contacts) and test the cable (continuity).

To open the headphone, carefully take off the earpad (it's held on with double sided tape, it can be reused) and then pry the driver out from the cup (it's simply pushed in, you need a thin tool to pry it out. More details here: https://www.head-fi.org/threads/dis...ould-help-with-re-cabling-and-modinng.618332/
It's for DT1350, but the procedure is the same for T51.

 

[Mad Max]

In addition to what was mentioned, also check the voice coil leads, make sure that they are not touching or criss-crossing. Make sure that they are intact and connected to the PCB where the main cable also connects to.

Circled in red below:

 

[yadako]

thank you so much dear sir! im into it now!

 

[CJG888]

Thinking of having mine recabled by Forza Audioworks (2m Claire OCC cable).

The recent acquisition of an Aune B1S amp has provided a perfect partner. They really open up...

 

[alspacka]

Hi there. The left cup on my T51p stopped working. When wiggling the cable it would cut in briefly sometimes so I guess the driver is fine. I had a look inside the and the contacts seem to be properly attached so maybe a problem further down in the y splitter or something.
So I'm wondering if anyone could recommend me a suitable cable? I don't really know what to look for. Also don't really know how to do it but I've got a soldering iron and some perseverance.
Would something like this be ok do you think? Thanks
https://www.ebay.co.uk/itm/3-5mm-Ja...air-Replacement/143801615960?var=442965918627

 

[rasmushorn]

It looks like a good option since it has the Y-split to two cords and the price is ok. As long as the cable is flexible and soft but that can be hard to see from the pictures. Right now I cannot find a suitable solution on Beyerdynamics own website. Maybe they have something if you contact them?

 

[rlisin]

Would something like this be ok do you think? Thanks
https://www.ebay.co.uk/itm/3-5mm-Ja...air-Replacement/143801615960?var=442965918627

I used this cable, the quality is decent. Diameter should be OK for T51 cups.

 

[alspacka]

Ok that's reassuring I'll give it a go, cheers

 

[alspacka]

This took me a while because I wanted an L jack so bought one from China. Worked out pretty well. Weirdly the biggest problem was getting the drivers to clip back in. It takes a fair bit of force even when seemingly alligned properly.
Seems like cable issues are quite common with these & I think like it might be partially caused by the hole on the little strain reflief bits being too narrow. The tension is focussed there instead of spread over the knot. Had to loosen them up a bit with a screwdriver.
Anyway I'm happy to have these back working, and it's not too difficult if anyone's worried about trying to do the repairs themself.

 

[siltsunrise]

You are very right about the strain relief being the culprit. Mine failed 4 times at that point. The thing is so tight and stiff, that the cable bends harshly at the entry, destroying the insanely thin wires inside. Best thing to do is do a detachable cable mod, which is what I am researching currently. Anyone know anyone in germany or europe who can do that for me? (Me and soldering iron = guaranteed death to electronics.)
Can someone recommend a great cable with less rubbing noise? What is the deal with those ones with 3 loosely braided wires?

 

[rasmushorn]

I just took my T51p out of the drawer after not having used them for a long time. They still sound very very god for a small portable headphone. I think it is time for them to come out more often.