A2000 Mouse problem

[funcle]

The mouse on my A2000 only moves vertically up & down. I've tried several other amiga mice, but it's still the same problem. Replaced the CIA chips, checked everything over several times and have about given up.  It did work momentarily on the boot menu screen after trying a couple different keyboard commands.  I think I may have placed the mouse into joystick mode (somehow), but have no idea if that's the problem or how I could return it to normal mode.

[Merc]

There's no mouse/joystick mode.  I'd guess since you've replaced the CIAs and tried other  mice that it's likely a fault (ie, cold solder joint) with the connector on the motherboard, or the line for left/right signal is damaged on the motherboard somewhere.  Have you tried gently wiggling the connector to see if it will work intermittently?  Could be all you need is to reflow the solder on those mouse port pins.

Hope that helps, and good luck!

P.S., it might be worth trying reseating all the custom chips (I forget which one handles the mouse ports now, maybe Paula?) in case you just have some corrosion on that one pin...

[TjLaZer]

The mouse on my A2000 only moves vertically up & down. I've tried several other amiga mice, but it's still the same problem. Replaced the CIA chips, checked everything over several times and have about given up.  It did work momentarily on the boot menu screen after trying a couple different keyboard commands.  I think I may have placed the mouse into joystick mode (somehow), but have no idea if that's the problem or how I could return it to normal mode.

Check this out:

http://www.rabayjr.com/Amiga/Flyer_Faq/toaster/mousdead.html

[Castellen]

The mouse on my A2000 only moves vertically up & down.

Given the fact that you still have movement, it's unlikely to be a problem with the 5V power supply to the mouse.

More likely to be an issue with the connector, one of the inline ferrite beads or with U202 (8 to 4 line multiplexer).  Very quick and easy to trace with an oscilloscope, keep moving the mouse and find where in the circuit the quadrature signal (will appear as a 5V rectangular waveform) stops.  Schematics here.

If you have no horizontal joystick movement in the other port, then the problem is likely to be downstream of U202.  In which case look at U4 (Denise) which reads the four multiplexed input lines.

[motrucker]

More often than not, this problem is caused by a bad connection in the mouse cable. Just test the mouse cable with a multimeter for continuity at each wire. The bad connection is usually at the plug end - caused by constant bending, and/or being pulled out by the cable rather than gripping the plug.
Hope this helps...

[funcle]

My mouse issue disappeared as quickly as it appeared.  Not sure if it was loose connections, hardware conflict or a software issue.  I'll keep an eye on it for awhile,, thanks for the responses!

[motrucker]

My mouse issue disappeared as quickly as it appeared.  Not sure if it was loose connections, hardware conflict or a software issue.  I'll keep an eye on it for awhile,, thanks for the responses!

Did you check inside the mouse to see if something was stopping the wheel/shaft for that direction from turning? You might just have a dust ball inside. If that is the case, just blow the mouse out with air to make sure the problem doesn't return.
Some times the simplest problem is the culprit!

[Pikkey]

The mouse on my A2000 only moves vertically up & down. I've tried several other amiga mice, but it's still the same problem. Replaced the CIA chips, checked everything over several times and have about given up.

I solved a very similar problem changing the DENISE chip.
Pin 8 and 9 of the Denise are used to drive mouse signals X/Y.
Try and let me know..

[CLS2086]

it's all explaned in the TJ's Link :

2) On the later model  Amiga 2000 systems this is usually due to a blown fuse, F1, on the A2000  motherboard, though the port controller chip is also a possibility;  early A2000 revisions did not have the fuse, so the chip is definitely  the source of failure.   For other models, it may be a similar fuse if  such exists, or the port controller chip.  Static can blow the fuse or  chip, but an attempt to use an incorrectly wired GPI cable on the  joystick port is another common cause.

On those models with a fuse, the fuse must be replaced, and is a  soldered-in component that looks like a resistor, but is green in color.   The component is located right behind the mouse and joystick ports.   You will  most likely wish to have a service center do the repair.

Or maybe, a broken track...