Most keys don?t work

Sam Cruise · November 2006

Hi there,

Nice to see all those Speccy fans out here,
i?m not alone :)

I just bought a used Sinclair Spectrum 48 k
but unfortunatly it has a major problem.
It looks magnificent, in the orginal box and everything.
Still only 8 keys seem to be working on the keyboard.
Only the ones in the middle of it, that is, b-n-g-h-t-y-6-7 (if i can remember it correctly).
What could be the problem ?
And is there anything i can do to fix it ?

kind regards from Iceland,

Jon

gtsamour · November 2006

The better way to entirely fix your problem, is to buy a new keyboard membrane from ebay (done it myself).
Spectrums keyboard membranes tend to wear out in the period of 20 yeard that have passed and the keys stop to respond.
They cost around 6 gbp for a rubber keys membrane and 16,5 pounds for a spectrum plus membrane.
They are easy replacable on the spectrum plus, abit more comlicated on a rubber keyed one.

Womble · November 2006

This is a common fault - simply just the result of age, it has 1 of 2 causes.

1) This is the one you want but by trying to fix this you might cause problem 2 anyway. The ribbons that attach the keyboard membrane to the keyboard have oxidised contacts and the keyboard has lost good contact with the main board. Unscrew the speccys case and you will see where these 2 ribbons connect - they just push into "grips" on the mainboard. Gentle wiggle them loose and re-insert - do not bend the ribbons or put too much strain on the cable as it goes into the keyboard assembly. That can result in fault #2, which may or may not be the problem anyway.

2) The keyboard membrane has died, the two ribbons that extend from the keyboard to the mainboard contain metal tracks just crack after years of being under the strain of being bent. If you can find the cracks (tricky) and fancy some micro surgery you can fix it with conductive paint and a tiny brush.

However these membranes are available new on ebay for about 6 quid but there is the problem of getting them installed without making the speccy look tatty.

If you unscrew the speccy you will find that the "lid" comes off and that the membrane is sandwiched beween the metal printed keyboard surround plate and the plastic underside of the upper assembly. The black printed plate ( the bit with all the green and red printing on) is stuck to the base with doublesided sticky tape - high tech stuff eh!. If you are lucky this sticky tape will have almost crumbled to dust with age and you will be able to lift the black printed keyboard surround without bending it. If the tape is still holding firm you will sadly bend the plate and the black paint will buckle and look really naff. Also when bent its nigh on impossible to get it flat again to try to stick it back on.

So you do have options, but you may end up with a fully working speccy that doesn't look quite as mint as it does now. Or you could buy a tatty one to play with and keep the minty one minty fresh.

gtsamour · November 2006

There are two ways to remove the metalic lid of the spectrum
1. use a hair dryer on the lid to heat it. the sticky tape underneath gives way easily when warm.

2. Soak the keyboard part of the spectrum in warm water for some hours (a day maybe). the plate cames out without much stress. The old membrane goes to the trash anyway so no worries.

(These advices were given to me by Ian Wolsey, which is an expert in speccy matters)

After replacing the membrane with a new one, you have to replace the double sided sticky tape as well. after cleaning the remains of the old tape with alcohol (NOT acetone), cut some stripes on new one and place them in places that would hold the plate enough. Don't put just 2 pieces or the plate will come off on its own.
Don't use too thick or too thin sticky tape.

I've done it myself and my speccy looks as it has never been touched by time nor human hand :)

Arda · November 2006

it's not easy to repair broken membrane with conductive paint either. Conductive paint is not very flexible, and when you bent the ribbons they tend to crack again. if you paint them while they are bent, your success rate can be higher.

I totally messed one of my keyboards, while I was trying to fix one row. they are gentle especially after 20 years of service :)

DEATH · November 2006

Sounds like you need a new membrane. Ebay is one place, possibly Sintech is another. But if you buy a ew keyboard membrane from RWAP so much the better - Rich has a fitting service, so you don't get a messed up metal top plate.

rwap · November 2006

DEATH wrote:

Sounds like you need a new membrane. Ebay is one place, possibly Sintech is another. But if you buy a ew keyboard membrane from RWAP so much the better - Rich has a fitting service, so you don't get a messed up metal top plate.

Thanks for the plug - certainly the hair dryer is about the best method.

I am also the one who advertises the membranes on ebay - cheaper on my website mind !!

I would love to find somewhere to make replacement metal top plates - we keep trying, but am unable to find anyone willing to deal in small quantities or even give a quote !! I guess about 500 units would be more than enough. There is a poll on our website for "faceplates" to guage interest, but alas without a manufacturer, it will never proceed

Rich
www.rwapsoftware.co.uk/membranes.html

DEATH · November 2006

Yeah, I know. I've already signed that "register your interest" list you have Rich. I assume membranes cheaper on your website due to Ebay fees etc?

Cheaky gits sent me a survey form via email. My reply wasn't what they were expecting I'm sure :)

Where I live, we have several big industrial estates where big firms operate - Ricoh, Maxell, Samsung, NEC, Miyutoyo (now closed), Tatung, Makita amd Siemens to name most of the main ones. There must be somewhere that'll make those face plates. Are you looking in the right places Rich? How about those places that deal with small businesses (business trust or something). I'm sure they'll be bound to know a firm somewhere that'll do the job for you.

For something that simple to make (with the right equipment), maybe the Chinese manufacturing industry would be a place to look. If your order is large enough, they'll be maybe a quid each at most, including shipping.

rwap · November 2006

DEATH wrote:

Yeah, I know. I've already signed that "register your interest" list you have Rich. I assume membranes cheaper on your website due to Ebay fees etc?

Cheaky gits sent me a survey form via email. My reply wasn't what they were expecting I'm sure :)

Where I live, we have several big industrial estates where big firms operate - Ricoh, Maxell, Samsung, NEC, Miyutoyo (now closed), Tatung, Makita amd Siemens to name most of the main ones. There must be somewhere that'll make those face plates. Are you looking in the right places Rich? How about those places that deal with small businesses (business trust or something). I'm sure they'll be bound to know a firm somewhere that'll do the job for you.

For something that simple to make (with the right equipment), maybe the Chinese manufacturing industry would be a place to look. If your order is large enough, they'll be maybe a quid each at most, including shipping.

Hope no-one thinks the survey form was to do with my site !! Not sure what you mean there.

Yes the prices are cheaper on my site due to ebay fees.

The problem with the faceplates is that I have sent 4 now to different manufacturers and get no response, emails to other people elicit no response - including some small engineering firms. The problem is the mix needed to form the curve on the plate, precision cutting and printing to ensure the right finish and all legends etc on the plate.

The tooling to create all this is the expensive part - and unless we are ordering say 10,000 plates, probably not worth it.

Any other suggestions ?? If lots of people try different manufacturers etc, we might just hit on something.

Rich

DEATH · November 2006

rwap wrote:

Hope no-one thinks the survey form was to do with my site !! Not sure what you mean there.
Rich

I thought it was obvious when I typed it, reading back, you're right, it isn't.

No, it was a bloody survey from Ebay, wanting to know the ins and outs of a duck's arse. I answered one question wrong by not checking a box and it crashed out, meaning I was supposed to start it again.

Not much chance of that happening I assure you. I just blew up and told them what I thought of their money grabbing illegal auction ignoring tw*tting site! I'd cut and paste it here for all to laugh at, but there's too many personal details.

Sam Cruise · November 2006

Thank you guys for your help
i´ve just purchased a new membrane for my speccy
hopefully everything will work out fine
i´ll let you know :)

Sam Cruise · December 2006

No problem at all !
I have put in a new keyboard membrane in my Speccy and now everything is working just fine :smile:
This wasn?t as hard as i thought it would be, allthough the metal plate didn?t come off to easily but using a hairdryer, heating it up first, it came off without any damage.
The hardest part perhaps was installing the ribbon into the socket without making any damage to the ribbon itself, but that all went well. 8-)

rwap · December 2006

Glad to hear that all went well - it is amazing just how many membranes we have sold over the past couple of years - it suggests that there is still a hardcore of speccy users, many of whom have never heard of World of Spectrum !!

Lets look forward to a good 2007

Rich

Most keys don?t work

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