Inserting Membranes

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XorA
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Inserting Membranes

Post by XorA »

Ok, having recently got a load of old zx81s most with cracked membranes, what is the trick for inserting then back into the molex connectors once shortened down?

The pins on those connectors seem far to stiff for the floppiness of the zx81 membrain.
sirmorris
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Re: Inserting Membranes

Post by sirmorris »

Hi,

you need to push them firmly _straight_ down holding in such a way that there's only a tiny bit of free end.

HTH

C
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Paul
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Re: Inserting Membranes

Post by Paul »

Hi XorA and welcome aboard.
I can ensure you that stiffening the floppy leads with a self-adhesive tape does only give you disadvantages.
And trying to help pushing in with some metal or plastic strip won't help either.
It's a thing of try and error. Those membranes were not all the same stiffness. Many had a little stiff part at the bottom for inserting purpose, but thats where they break first :(
I shortend a quite good looking menbrane on my QL recently four or five times not giving the wanted result. Trying to save some money isn't always fun.
You get replacement membranes at sellmyretro.
They are very good value for money and inserting them will give very good results on the first try. And they will most probably last a long time.

If you could dispense a working zx81 mainboard, probably (not necessarily), an issue3, I would be interested as my Zeddy is VERY unstable at the moment.
Maybe in exchange against a new membrane from Rich? I would have him send to you while I pay for it, and you send me a board to Germany?
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1024MAK
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Re: Inserting Membranes

Post by 1024MAK »

I use a very very thin piece of white card (cut to shape) to "open" the spring contacts in the connector first. Then I insert the membrane tail into the connector keeping the cardboard between the tail and the contacts. I then gently remove the cardboard.
It is still tricky, but having the cardboard helps to prevent the contacts from bending or breaking the membrane tail.

Mark
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RWAP
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Re: Inserting Membranes

Post by RWAP »

I have no problem using the latest membranes - just simply hold both sides of the tail end with thumb and forefinger and slide in :)
XorA
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Re: Inserting Membranes

Post by XorA »

Hi RWAP, I am planning to get your membranes for the machines which have crumbled so much that there is nothing left of the ribbon (there is at least one, it literally disintergrated into flakes). But there is also some joy in repairing using the original parts.

Using a combo of Mark and sirmorris method seemed to work best.
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PokeMon
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Re: Inserting Membranes

Post by PokeMon »

I would change the whole keyboard membrane and replace against a new one.
The membranes from RWAP are perfect and easy to replace. ;)
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