A1200 keyboard - garbled input

[syphus]

Hi there! Long time since I registered here, so I'm starting over again.

I've been chatting to Akira about this problem since last night, so I'll recap as best I can...

One of my A1200s is suffering from insane keyboard input garbling at the CLI. There are boot issues, but I suspect they're just down to the fact that I haven't tidied up my startup-sequence since swapping my 030 out of this machine and putting an 060 in. So that's not my worry: I'm booting to one of my own rescue floppies which gives me a shell.

Typing 'qwerty' might result in 'q3[]78'. Hitting 'Return' might result in a successful return-carriage, but might equally send an up-arrow signal and bring up the previous gibberish I typed *Sometimes* I hit a key harder and it sends the correct signal, but I think this is just my imagination - wiggling the keyboard connector doesn't make much difference at all. I've pared down the ribbon cable and readjusted the sticky layer, all to no avail. Actually, I trimmed twice and now it doesn't seem to work at all, but I think that's just because my second trim was wonky (late last night) and the voltage might not be connecting.

This is the machine I used to use for live performances and it was problem-free for an entire UK tour as recently as September '08. (Now I use one of my A600s as it fits great in hand-luggage ). So since the last tour, it's been sitting in my flat and hasn't been switched on since the 3rd of December, when the keyboard worked fine. Then I played in New York for a week, so the flat was probably FREEZING while I was away (though the heating came on a few hours a day) and over Christmas it's been in my bedroom - very badly insulated, cold in the day and warm in the evening. Heating goes off at midnight and it's -3C outside in Newcastle at the moment.

Why this incredibly boring set of facts? The only thing I can think of now is that the fairly extreme fluctuations in temperature could have caused me some serious problems. The machine's experienced no significant knocks - let's face it, Amigas are as tough as old boots... though I've always felt that the only structural weak-point in the A1200 is the keyboard connector... (I hope it's not the socket's connection to the motherboard!). So perhaps the ribbon pops out from heating/cooling (expanding/contracting) too much? Well reseating and trimming didn't help, so maybe it's not as simple as that.

Could temperature troubles cause a capacitor to blow? Do capacitors tend only to blow when there's charge through them, or could it be damaged by the cold and then blown when you next switch the machine on?

The only other thing I can think of is the keyboard controller chip... But I doubt things are so bad that surface-mounted ICs are going to start leaping off their motherboards By the way, I reseated my ROMs but everything else has been behaving fine anyway.

For the record, this A1200 is unmodified, has no spliced power lines, nothing like that. Before I went to bed last night, I ordered some new membranes from Amigakit - if one of those solves it, it'll be a relief; if not, they're handy spares to have for my other A1200s

Sorry for the length - hope it doesn't cause too many tl;drs. Does anyone have any suggestions? Cheers!

[Yoto]

Hello syphus!

I had similar problems with my Amiga 1200 keyboard, some keys were missreporting too.
I found the problem after i open the keyboard board, the membrane had some humidity, and some of the links were rotten, if some links dont connect correctly some keys may report different functions.
A word of advice, if you have condensation issues, store your Amiga in a large plastic box, it also helps to add along a couple of silicon bags.

Hope this helps.

[DH]

Welcome back mate!

I agree in you getting new membranes, maybe the others got a little moisture between the membranes which is causing a short of some description.

This happened to my daughters PeeCee keyboard when she spilt fizzy pop all over it. I had to strip the whole thing down 'n' clean it and wait till it was dry properly before sandwiching the two together before trying it again. Worked fine. I did, however, apply a small amound of WD40 just to help remove any moisture that may of still been present + it's good for making a good electrical conection too.

btw. I'm just up the road from you mate!

[syphus]

Guys, that's great to hear! Encouraging not to have to fork out money I don't have on yet another A1200, and also encouraging to think that it's not a cap failure. I'd hate to think that this was the beginning of the end for all my Amigas' capacitors

Particularly glad to hear "some keys may report different functions", because I didn't turn up any results on the net for that fault - just lots of reports of dead keys (which is what I'd expect from a straightforward ribbon/connector fault).

Demon - ah, cool! Did we trade my PPC/060 for your 1260 in the Gallowgate carpark in the middle of the night a few years ago? Perhaps that was someone else. There's also a possibility we've drunkenly talked Amiga in Trills/Mayfair/Cuba/Legends, but I wouldn't want to put money on it. There are some fuzzy memories in my past...

Cheers again, both.

[DH]

Originally Posted by syphus

Demon - ah, cool! Did we trade my PPC/060 for your 1260 in the Gallowgate carpark in the middle of the night a few years ago? Perhaps that was someone else. There's also a possibility we've drunkenly talked Amiga in Trills/Mayfair/Cuba/Legends, but I wouldn't want to put money on it. There are some fuzzy memories in my past...

Cheers again, both.

Don't remember trading anything Amiga and If we did ever talk Amiga I was Probably too drunk to remember

Tis a shame about the Mayfair, was an excellent place to meet and an awesome place to indulge some alcohol too. Cant believe they trashed it for the Gate, but then I suppose times have to move on, still, it's a shame

[JuvUK]

One of my A1200s is suffering from insane keyboard input garbling at the CLI. There are boot issues, but I suspect they're just down to the fact that I haven't tidied up my startup-sequence since swapping my 030 out of this machine and putting an 060 in.

agreed on the keyboard, but you sure about the 030 startup-sequence? in my experience it's the incorrect or lack of 060 drivers that causes all the stability woes, you using blizzard or apollo m8?

cheers JuvUK

P.S i'm a long way away from you lol

[syphus]

Mayfair - shame indeed! I only went a few times when I was 15, then it was shut.

JuvUK - aye, I think it just needs an extra WAIT which it didn't need when the 030 was in (or some similar fiddly thing). I've moved over all my 060 libraries and dummies, etc. so I'm fairly sure that's unrelated. It's a Blizzard 1260/50mhz. Worst comes to the worst, I'll just scrub the install and copy in the WB backup I took from another A1200 when the 060 was in that

[DH]

Originally Posted by syphus

Mayfair - shame indeed! I only went a few times when I was 15, then it was shut

You missed a huge amount of fun then mate! I started going in the mid 80's

If you do clean the membrane and use WD40, be sure to allow the WD40 to dry before joining them back together. Maybe leave overnight near a radiator or something nice and warm

btw. Only use a small amount, don't saturate it, but I'm sure you already know this

[syphus]

but I'm sure you already know this

I wouldn't have known to let it dry overnight, so cheers!