Cleaning ZX81 16k RAM pack and edge connector

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hinotor1
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Cleaning ZX81 16k RAM pack and edge connector

Post by hinotor1 » Mon Mar 11, 2019 10:29 am

Hi All!
I wondered if anyone would share their personal advice on the best methods for cleaning the 16K RAM pack and the edge connector on the zx81.
Thanks! :)

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1024MAK
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Re: Cleaning ZX81 16k RAM pack and edge connector

Post by 1024MAK » Mon Mar 11, 2019 11:01 am

First, to remove any oils or grease (from people handling it) clean the edge-connected and the socket with IPA (Isopropyl alcohol) using a toothbrush (but not one you use for your teeth, buy a new one for this). Be careful and don’t splash any IPA in your eyes. Then use a cloth or paper towel to finish off.

If the edge-connector on the ZX81 (or indeed, any edge-connector where tinned finger contacts are used (a dull silver colour)), needs further work, use either a eraser designed to remove ink (NOT one designed to remove pencil lead) or a ‘PCB cleaning scrub block’.

Alternatively use a ‘fibreglass abrasive pencil’ / ‘glass fibre cleaning pen’.

In all cases, make sure you don’t breathe in the dust that is produced. Collect up the dust and dispose of it properly as the dust will contain lead.

Finish up with another clean using IPA.

When cleaning, you are looking to just take the surface layer off so that you get a nice shiny silver colour. If you get down to the copper layer, stop cleaning.

Mark

paul ron
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Re: Cleaning ZX81 16k RAM pack and edge connector

Post by paul ron » Mon Mar 18, 2019 2:26 pm

To clean female edge connectors that are heavily oxidized, I fold a piece of wet dry 400 abrasive paper to form a male and push it in n out a few times.

Cleaning the males, use a pencil eraser n go over the fingers till they are nice n shinny again.
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