Trying to fix my ZxSpectrum+

For experts to discuss very technical stuff and newbies to ask why the Spectrum they bought off ebay doesn't work.
Hyuma
Berk
Posts: 34
Joined: Sat May 18, 2019 6:43 am

Re: Trying to fix my ZxSpectrum+

Post by Hyuma » Thu Aug 08, 2019 10:02 pm

I want show you something curious...
Image

In this picture, you can see on my mat a white/beige shadow line pointed by my red probe. That is the result after cleaning the black dirt from the membrane. Seems like that IPA removed with the dirt also the conductive material of the tracks on the membrane :o. So after the cleaning I've 0 keys working and I will buy one new the next weeks. I don't know if that is the result of corrosion or not, but on my mat now I have some some part of the membrane's tracks :lol:.
0 x

User avatar
1024MAK
Manic Miner
Posts: 512
Joined: Wed Nov 15, 2017 2:52 pm
Location: Sunny Somerset in the U.K. in Europe

Re: Trying to fix my ZxSpectrum+

Post by 1024MAK » Fri Aug 09, 2019 4:43 pm

Yeah, I strongly advise against using IPA or any other solvent cleaner on any keyboard membrane.

For cleaning the plastic part of the membrane, only use a cloth moistened with soapy water, then another with clean water, then dry.

For the conductive copper "strips", you have to be rather careful as they are only a thin film. Apart from the areas where they connect to the PCB connector, and the area where two membrane layers connect together (plus keyboard only), don't worry about them going black in colour. The black colour may well be tarnish due to the copper actually being an alloy rather than pure copper (which goes green rather than black when exposed to moisture and oxygen).

Having said all that, it was probably unrepairable anyway.

Mark
1 x

User avatar
Muttley Black
Dizzy
Posts: 87
Joined: Wed Apr 03, 2019 2:31 pm

Re: Trying to fix my ZxSpectrum+

Post by Muttley Black » Sat Aug 10, 2019 5:24 pm

Now that you job is done and you have a working spectrum, don’t forget to give a good cleaning to your motherboard with isopropyl alcohol and toothbrush.

It is very important. I saw lot of flux on your soldering work.
1 x

Hyuma
Berk
Posts: 34
Joined: Sat May 18, 2019 6:43 am

Re: Trying to fix my ZxSpectrum+

Post by Hyuma » Mon Sep 09, 2019 8:18 pm

Hey long time i didn't post nothing, this week i'll go to an important flea market for electronic in Modena. I hope to find some spare parts for my ZX (rubber keyboard, capacitors, etc..). Lately i was busy to repair some C64. :lol:
0 x

Post Reply