my keyboard doesn't work

[Harrison]

The first thing to check is that it is connected to the motherboard correctly. To do this you will need to open it up. This isn't hard as it just involves removing the screws along the front edge ender the Amiga and a couple down each side underneath. Once done the case should come apart and the keyboard can be lifted free. The keyboard is plugged into the motherboard by some wires at the back in the middle. Try unplugging it and then plugging it back in correctly and see if this fixes the problem.

If not then it could be a fault with either the keyboard itself or one of the chips on the motherboard.

[muscken]

thanks a lot, tomorrow i will try.
thanks

[muscken]

i've removed the cover, I tried to remove and replace the keyboard pin from the board but nothing has changed.
here there are some photos, maybe they will be helpful. what is that flying metal cable under the keyboard?
other ideas / attempts?
thanks a lot!

http://imageshack.us/photo/my-images/502/p1010207s.jpg/
http://imageshack.us/photo/my-images/546/p1010208x.jpg/
http://imageshack.us/photo/my-images/841/p1010209t.jpg/

[Harrison]

I don't know what that metal cable is shown in your last image. I don't think I have that in any of my A500s.

Does the caps lock led blink at all when you switch the system on? If so how many times?

• One blink: Keyboard ROM check failed.
• Two blinks: Keyboard RAM check failed.
• Three blinks: Watch dog timer failure.
• Four blinks: A short between two lines or the special control keys.

Don't worry if it flashes once as this is normal when any Amiga boots. The blinks will happen on a loop so you will know.

It is isn't blinking then we can rule that out.

The next thing you can try is to see if the CIA chips are faulty on the motherboard. There are 2 of these chips that control the keyboard and mouse. To test faults you can swap them over, as this will then show the keyboard working and the mouse not working, if that is the cause. The two CIA's are both 40-pin chips that are marked CIA ODD and CIA EVEN. Simply swap them over, making sure that you have placed them in the right way, then power the Amiga back up and see what happens.

[muscken]

hi harrison, thanks...the caps lock light doesn't blink, it's always on (like the first picture that i've posted).
where are this two chips? on the mainboard?

p.s. in another forum somebody told me that metal cable is grounding...

---------- Post added at 10:02 ---------- Previous post was at 09:14 ----------

i've found this photo
http://www.flickr.com/photos/lu6fpj/2745203804/
where are the two chips? the two near keyboard connector?
thanks

[Harrison]

That picture looks like a very early revision. All the ones I've seen have green motherboards with much clearer writing on the board labelling the sockets.

On that picture the 2 CIA chips are in the middle towards the back of the board. The CIA ODD A chip is directly to the left of the keyboard cable header, and the CIA EVEN B chip is the one directly below the floppy drive cable and to the right of the floppy drive power cable header. See them now?

Here is a later (newer) a500 motherboard:
http://www.tk-webart.de/images/amiga...oard-Rev8a.jpg

In this second picture you can clearly see the 2 CIA labelled sockets. This images has the ODD CIA chip removed from its socket.

[muscken]

maybe in these weeks i'll receive another a500.
i wanna try to switch the keyboards. its a problem if they are different a500 version?
thanks