Help me fix my grail ZX 128k Spectrum

Beaps

Sorted I set the iPod to 'small speaker' wow I am on a roll. Happy days

britain4

I have used my headphone amplifier to good effect for loading games into my 48k from the excellent Speccy Tape app on my iPhone so that does work if the levels are still too low (glad you got yours sorted!)

Beaps

I also got one of these, is it 128k compatable?

eBay Item number:
301229798143

zedexspectrum

Have A Look At This Mate Just As A Backup.

Ebay Item Number

281138097707

http://www.ebay.co.uk/itm/281138097707?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3D281138097707%26_rdc%3D1

And I Have One Of The Same Interfaces I Believe Its Switchable Between Cursor And Kempston Mine Works Ok On My +128

Beaps

Back again lol

I bought one of these from eBay

http://www.ebay.co.uk/itm/121389542214?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

I tested it in my 128k and I can only get ENTER to work. I then tested it on my 48K+ and get like 60% of the keys working.

Has anyone had any problems with these, I messaged him back but it was the weekend and I got an out of office.

Glenn

It says on the listing that the seller is away until the 16th, so probably on his hols.

Beaps

Didn't see that lol

I was more interested to see if others have bought one and had not problems.

balford

Make sure and follow the instructions about tightening the screws on the membrane and the keyboard tail clasps to the letter - if these aren't tightened progressively and evenly (but not too tight), then you'll have problems.

Loosen everything off and retighten in a spiral pattern, working from the centre out. Just tighten until you feel a little resistance, then keep working out.

Lastly start from the centre again and nip the screws up another turn or so.

The above should work, if it doesn't rinse and repeat till it does :) Golden rule - don't overtighten anything!

B

Beaps

Nothing... Lol

I tried another one I had out of a 48k + and.... Nothing

I think maybe the keyboard chip is bad, maybe?

balford

Does the new membrane work if plugged into a 48K? (You can take the 128K top case half and just plug it into a 48K PCB as is to test.)

There's no 'keyboard chip' in the Spectrum design, that functionality is handled by the ULA. It wouldn't be common for this to fail.

B

Beaps

I tried it on the 48k and again and only the enter key work. I can't move up/down to get into basic to test the other keys. I also press Caps Shift and 6 and nothing

That's why I asked has anyone had a faulty one of these. I have tried fitting this like x10 now.

Trafferth

I had a "faulty" new membrane which seemed to work just fine until I screwed down the case. It turned out that some of the plastic covering the membrane leads had worn away and some of the traces were exposed.

These traces then came into contact with the modulator casing (ground) when the case was closed and none of the keys worked. A bit of insulation tape around the worn area to isolate it did the trick and the membrane works fine.

A long shot, but worth a check - only a small bit of the trace(s) needs to be exposed for this to happen...

Beaps

If I try the 48k one back on the 48 as I said I get some keys to work. If I press 'up arrow' and press a key that works the fonts jump from caps to none caps. I take it this means the 'up arrow' is working.

If I then take it off and plug it back into the 128 and press the arrow key, I get nothing.... Weird hey

Beaps

I even tried the membrane on the backing with the silicon over top to make sure i pressed in the key presses 100% it was hitting the centre and still nothing

Glenn

Do you have a known fully working 48k spectrum? If so, try the keyboard from that and vice versa..

Beaps

No as the I got a new membrane for the 48k also as the old one was missing keys. Even if I try the old one from the 48k in the 128 I get nothing.

balford

By any chance are there remnants of the old keyboard tails in the 128 keyboard sockets?

You could also try snipping a piece of the old tails (the non-conductive bit) and using them as extra padding for the new membrane ends, in case they aren't making proper contact in the sockets.

B

Beaps

Good idea, let me try that.

Beaps

Ohhhhhh yer, I am doing the moonwalk right about now, it works.

Its was funny tho as when I looked at the bottom of the new membrane you could see it was catching all the lines, any how that has sorted it.

balford

Sweet, another one fixed :)

B

Beaps

Only thanks to the WoS guys THANKS, I'm offski to play some Auf Weidersehn Monty

Beaps

Just done the same to the 48k+ that only some keys was working and....bingo, that all works now.

Thanks again!

Glenn

Brilliant and well done! :)

1024MAK

See Beaps can fix 'em :-)

Well done :D

Mark

Beaps

I do try :lol:

Just one more thing, what adapter (joystick thingy) do I need for the back (can you post a link) & what setting do I choose with it. Interface II, Sinclair, Cursor, I never know and get confused. :confused:

balford

Ben Versteeg sells new joystick interfaces (Kempston compatible) here.

Alternatively there are plenty on eBay, if you post up one you're interested in and are not sure what setting to use, one of us can give you that info.

B

Beaps

here is what I got



No1

- Did nothing when I selected Interface II
- Did nothing when I select Cursor
- Actions all wrong, Fire to walk etc on Kempston

No2

- Once I selected Interface II, crashed the Spectrum

Glenn

Tried any of them on Kempston? Pretty sure the RAM one will be kempston.

**EDIT** Does the first one have a switch on the back?

balford

No idea what the first one is, but the second is a RAM Joystick interface, and is Kempston compatible.

B

Beaps

Glenn wrote: »

Tried any of them on Kempston? Pretty sure the RAM one will be kempston.

**EDIT** Does the first one have a switch on the back?

No mate, no switch on the back