I have had the Line Module ZM-4 for a little while now, and suddenly, it is no longer detected 90% of the times I turn on the OP-Z. I have to take the back off, remove the module and re-insert it and close up and it works just fine. This is with power on or off. It DOES Hot Swap. I am going to write an email to TE, but I wanted to hit up the group first. Thank all.
maybe try cleaning both hte contacts (module side and Z)
w/ a qtip w/ a lil deoxit or high % isopropyl dabbed on?
costs u relatively nothing to rule out if nothing else 
hope its not due to the warping or whatever else that ppl have trouble with their modules
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I hope so too, if it’s the warping, that would really suck, it works after replacing, so it’s confusing. I will definitely try that. I don’t know. why I haven’t yet. I’ll report back with a SITREP, lol. All the best.
You could forward this info to TE.
I had the same problem a month ago, it only started immediately after I got it.
They asked for my op-z serialnumber and told me the OP-Z was the problem and I had to send it to them,
and when they get it they would send me a new OP-Z.
I bought the OP-Z in 2019. And now I got a brand new Z and the line module works perfect, as perfect as the service I got from Teenage engineering.
5 Likes
Starting a ticket now!
Replacement unit is on the way!! 
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Nice! It didn’t work for me so I used some patafix glue pad to make it fit more appropriately within the OPZ. Even for the popping encoders I put patafix inside (at the beginning it was not perfect but now everything is well fixed). I would not advise to do the same as I don’t know in the long term how it will go
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