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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: petercli on May 04, 2014, 06:18:35 PM

Title: Amiga 1200 keyboard problems...
Post by: petercli on May 04, 2014, 06:18:35 PM
Today I  put  a  ACA1232 card into my amiga.
 
 the amiga booted up , but some keyboard keys were not working. example:I want to type 'CPU' to test my card. The 'c' does not work, but 'p' does .
 
 So I reseated the keyboard ribbon . Now the h.disk light stays solid on , and I don't get any video.
 
 I found this article : http://eab.abime.net/showthread.php?p=597612

DO I need to start cutting up the ribbon cable? What is a  A1200  keyboard membrane   ?
 
 Thanks in advance, Peter
Title: Re: Amiga 1200 keyboard problems...
Post by: Oldsmobile_Mike on May 05, 2014, 06:06:16 PM
Dumb question, but why did you have to remove your keyboard to install the ACA card? Shouldn't it have just slotted in from the bottom?

I'd re-check all your connections and your installation, especially check that nothing on the keyboard is coming in contact with anything on the motherboard (maybe related to your second issue). The ribbon on the A1200 keyboard can be repaired in various ways, but IMHO this is a huge pain-in-the-a**.

You don't say where you're located, but AmigaKit has new A1200 keyboards in-stock for under $40, just getting a new one to test might be your easiest option. Good luck!

http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=336
Title: Re: Amiga 1200 keyboard problems...
Post by: petercli on May 06, 2014, 12:58:27 AM
Hi Mike,
 I was doing some other modifications,   like taking out the rf shield etc.
 
 I was able to boot ok, but some keys didn't work. so I reseated the ribbon cable. That's when the weird stuff started happening.
 My main question :  can a bad keyboard ribbon stop the amiga from booting?
 
 I saw the keyboard on amigakit,  but it says English UK .( I live in USA )
Title: Re: Amiga 1200 keyboard problems...
Post by: danbeaver on May 06, 2014, 02:43:57 AM
In theory, the pressing of certain keys could screw up a boot sequence, but the fact the keyboard worked before it was manipulated, means that it is likely a contact issue with that ribbon cable -- either it is inserted off angle, or poorly inserted; pull it out and clean it gently with the rubber end of a pencil, then try to insert it back in as straight as possible.

The keyboard itself it made cheaply with a "membrane" with 2 small carbonized rubber pads for each key; the keys have a "U-shaped" carbonized rubber piece that crosses the two contacts.  Unfortunately the membrane uses a glue easily dissolved by alcohols, so one has to be gentle in cleaning it.  Here you can rub with the eraser, but wipe with water.

The UK keyboard works like an American, but there are a few keys off.  You can buy the stickers to put on them off idiotBay if you can't remember the differences.
Title: Re: Amiga 1200 keyboard problems...
Post by: petercli on May 07, 2014, 11:56:38 AM
I solved the problem !
 Turns out the problem was caused by the hard drive cradle - it must have been creating a short because after I removed it everything works great.
 Thanks guys for your suggestions.
Title: Re: Amiga 1200 keyboard problems...
Post by: danbeaver on May 07, 2014, 04:02:45 PM
Yes!  A simple answer.  "I love it when a plan comes together."