Problems to mouse ports

[TheDarkCoder]

Hi

suddenly the mouse port of my A4000 does not work properly: the mouse does not move vertically. Horizontal movement and buttons still work. I tried with mroe than one mice, unfortunately the problem is in the port.

Similar problem, with my A4000T. The joystick port does not work. In this case it seems that the port reads strange signals. Some times it reacts to joystick commands, but in a strange way (for example, button alone does not work, but button+up is recognized as button).

Any suggestion?

[voyager_1701e]

Has the battery been changed in your system? Leaky batteries around the area which contains the chips for the port interface is very common. Hopefully that's the problem as its a relatively easy fix.

[TheDarkCoder]

Originally Posted by voyager_1701e

Has the battery been changed in your system? Leaky batteries around the area which contains the chips for the port interface is very common. Hopefully that's the problem as its a relatively easy fix.

The battery in the A4000D was changed in 2004... I have to check, but the battery still works ok.

I removed the battery from the 4000T (and use external AA batteries), so for it this is not the problem

[Kin Hell]

Have you tried another mouse in the A4000D?
If it does the same, I guess one of the CIA Chips is shafted. There are two of them iirc. One controls the 9 pin ports & the other the Floppy & IDE headers & maybe something else too. I can't remember which does what either, but hot swapping on the 9 pin ports is not a healthy practice. Not healthy on any Amiga port tbh.

[TheDarkCoder]

Originally Posted by Kin Hell

Have you tried another mouse in the A4000D?
If it does the same, I guess one of the CIA Chips is shafted. There are two of them iirc. One controls the 9 pin ports & the other the Floppy & IDE headers & maybe something else too. I can't remember which does what either, but hot swapping on the 9 pin ports is not a healthy practice. Not healthy on any Amiga port tbh.

yes, I tried with a different mouse, the problem is in the port

[Hewitson]

Originally Posted by Kin Hell

hot swapping on the 9 pin ports is not a healthy practice. Not healthy on any Amiga port tbh.

I disagree with this. I have ALWAYS hot swapped joysticks/mice on my Commodore computers, and I have never done any damage whatsoever. As long as you don't touch the pins there's virtually no risk involved.

[FOL]

For A4000T, try checking two cables, long and short.
Used to get same issue, when I had A4000T apart.

For A4000D, check the port latching chips, next to the clock latching chip.
Could be corrosion damage, also check port itself for damage/pushed in pins.

[Daedalus]

Does the mouse pointer "jitter" up and down by 1 pixel when you try to move it? If it does then the problem is with one of the y-lines. If it does not, it's very unlikely that both y-lines were damaged at the same time, so it could be one of the chips on the motherboard.

Also, the two y-lines are used for the joystick, up and left. Have you tried a joystick in that port?

[TheDarkCoder]

Originally Posted by Daedalus

Does the mouse pointer "jitter" up and down by 1 pixel when you try to move it? If it does then the problem is with one of the y-lines. If it does not, it's very unlikely that both y-lines were damaged at the same time, so it could be one of the chips on the motherboard.

Also, the two y-lines are used for the joystick, up and left. Have you tried a joystick in that port?

Yes!

It does "jitter"by 1 pixel! Good spot!

I tried a joystick, everything works except the up direction (left also work). I tried with Super Street fighter. When the joystick is used to move the cursor to select the character's player, or the location, it is not possible to move up. Instead, during the match, if I don't move the joystick, the sprite always jump as if the joystick is always up.


So if it is a problem with a y-line, could it be corrosion by the battery?

[Kin Hell]

Originally Posted by Hewitson

I disagree with this. I have ALWAYS hot swapped joysticks/mice on my Commodore computers, and I have never done any damage whatsoever. As long as you don't touch the pins there's virtually no risk involved.

Being careful always helps, but it can go pear shaped when the mouse/joystick connector has a metal band around the outside of itself. It's just all so easy to spark a few pins whilst aligning it to push in. Bye bye Mr. CIA Chip.