I almost repaired an LCD 2, an audacious catastrophe.

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croak

R.I.P. 28 June 2021
Joined
Mar 28, 2007
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I was given an LCD 2 headphone which had stopped functioning on the right channel.  It measured open circuit and the odd intermittent reading made me suspect the connection to the membrane which are made with a lug, bolt and nut and serrated washers.  You can not tighten this properly without stripping the driver. 

I managed to take it apart.  Took the bolts and nuts holding
It together  out.  Then you need to pry the slotted metal plate on the front of the driver off with a strong thin sharp blade.  It?s glued together. 

In my case not all the bar magnets stayed attached to the plate. 
3 stayed behind in the ?frame?.  Lying loose barely kept in place by the magnetic fields.

I measured for a while,  tightened the lug bolts  from one side and kept getting bad readings and I suspected a crack in the membrane track. 

Eventually proper tightening with two spanners gave me a nice solid 49 ohm reading.  Yay!!  Jubilation and excitement.

And then i started to look at re assembly.  That?s when one of the loose magnets moved and attached itself to its friend on the other side of the membrane. 

I could see the damage right away.  Ripped membrane and tracks. 


So, hoping for 2 things.  Maybe someone had a driver fail and got new drivers  or even abandoned their lcd 2. I would be happy to purchase a used lcd drive unit. 
A new matched pair costs too much for now. 

Also, someone else with the same problem may learn from my experience.  Which is the cheapest experience. 

This is the one connection screw.  They must be tight. 
You need an imperial Allen key and
Small socket and driver. 


f3efef54105298f984eeb0ca40cbafda.jpg





If I did it again and some of the magnets came loose from the plate, I would recover them carefully from the gaps before anything else.
Best would be a non magnetic plier of sorts.  Else flip up one side slowly leaving the other side locked in its ?catch? and as soon as you can, lift it out completely.  The membrane is fragile.  The magnets powerful and hence brutal.  You need to mark them for place and polarity if you can.

You will need to clamp and glue them back on the plate before trying to re assemble anything. 

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The audacious catastrophe:

c015e0fec4ee559523144a896fc25341.jpg
 

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