mouse ports not working

[maurizio55]

Both mouse ports are partially not working on my Amiga 4000/30. Buttons work (I can right/left click), but not the movement detection.
It's not a mouse problem, the same mouse works on a different Amiga, so it has to be a motherboard problem.
I wonder if there is a way to easily detect where the problem can be, maybe changing / replacing the dedicated I/O IC on the board?

Please help if you can: I need to transfer tons of data to PC and moving the cursor with the keyboard (A-arrows) is not the most comfortable way do work...

Thanks

PS: Hi have 3 more Amigas: a 4000/40 (not starting at all), a 500 w/HD - working perfectly, and a veeeery old (non working) A/1000, from 1985 with a noisy custom made 10MB HD.

[commodorejohn]

I had the same thing happen with my A2000 - it turned out that a fuse needed replacing. I'm not sure if it's the same for the 4000, though.

[Cammy]

Where abouts are you? If you can't repair them yourself there may be an Amiga repair center you can send the motherboards to for repairs. It's very likely all the capacitors need to be replaced as they do on nearly all Amigas eventually.

[Jope]

Measure / replace the ferrite bead that is right next to the joystick port. You are probably missing +5V to the ports.

The aforementioned fuse in the A2000 blowing causes the same symptoms, but the A4000 doesn't have that part.

[Thomas]

Buttons work (I can right/left click), but not the movement detection.

Is the keyboard lock locked?

Please help if you can: I need to transfer tons of data to PC and moving the cursor with the keyboard (A-arrows) is not the most comfortable way do work...

Connect the harddrive to your PC and use WinUAE to transfer files. It's much faster than any networking or external harddrive solution for the Amiga.

If you don't want to use the mouse, then use a DOS shell (CLI). DOS commands can be entered using the keyboard only and are much more flexible than Workbench drag&drop.

[JimS]

If you have a voltmeter, measure carefully between the center two pins of the bottom row of the joystick port. There should be 5v there. If there's really no fuse, a trace might have opened up.

[glitch]

As a temporary workaround - have you ever seen or tried the program SerMouse?  I downloaded it years ago from Aminet.  It allows you to use a PC serial mouse on the Amiga's serial port - if you have one of those old mice kicking around - that might make things easier for you.

[jj]

Wouldnt this point to broken CIA ?

[JimS]

Not really... the CIA controls the buttons. The mouse directional signals go thru Lisa and the paddle signals go thru paula.

[smariotti]

I have this same problem on my A500.  It started happening shortly after I moved my computer from one desk to another and seemed to just spontaneously stop working.  

Like the OP the mouse buttons work fine, but I can't move the mouse at all.  I tried my mouse on another Amiga and it works there, and I tried another Amiga mouse on my Amiga and got the same result (buttons work, no motion.)

It sounds like it's a fuse that's blown on the mouse port. I haven't yet taken out my multimeter to continuity test the fuses at the port, but I disassembled the Amiga and see where there's a bank of resistors and fuses near port 0.  I suspect that one of the fuses is blown and I will have to replace it with another fuse.  It seems like the Littelfuse Pico II fuses are the same type.  I need a 100mA replacement from what I read... these seem to run about $5-6 USD which seems a little expensive for what it is.

Has anyone had this problem on an A500 or has anyone else replaced these fuses with something else?

[_ThEcRoW]

I have a similar problem on the mouse port of my a1200. Only work buttons, not movement.
I had to use a port splitter on the second port and use setmport to reroute mouse in workbench. If it's related to the problem here, i would like to know a possible solution, as some games won't recognize the ports on second port, and it's annoying.

[smariotti]

If you have a voltmeter, measure carefully between the center two pins of the bottom row of the joystick port. There should be 5v there. If there's really no fuse, a trace might have opened up.

I tested both joystick ports and measured +5v between the two pins mentioned, so it would appear my fuses are ok.

Yet I still have no mouse, just buttons on port 1, don't know how to switch ports to try the mouse in port 2 if that's possible.

It looks like the resistor at EMI401 is burnt.  I can't make out the color bands, but the first one is green.  Available documentation suggests that this is a 1 Ohm resistor, though clearly mine is not.  The burned/scorched parts hide the colors of the other bands and I can't find anywhere that lists the resistor value for EMI 401 on my A500 rev 5 motherboard.  I suspect the value of the resistor is different on different revisions and I don't want to put the wrong value in there!

Anyone else have a rev 5 that could give me the color bands of EMI 401 ?  (It's near the JOYSTICK 2 port)

I'm guessing based on a few pictures available (all hard to read, sadly) that it's GREEN-BROWN-SILVER-GOLD or something close to that, which suggests 0.51 Ohm.

http://www.bboah.com/download_photos/a500mb_rev5_2.jpg
http://www.bboah.com/download_photos/a500mb_rev5_3.jpg

[Darrin]

This might sound stupid, but have you tried a different mouse?  (Easier said than done I guess as most people usually only have 1 Amiga mouse...)

[Castellen]

I've published a brief fault/repair guide on typical A4000D mouse issues here.

[JimS]

I tested both joystick ports and measured +5v between the two pins mentioned, so it would appear my fuses are ok.

Yet I still have no mouse, just buttons on port 1, don't know how to switch ports to try the mouse in port 2 if that's possible.

It looks like the resistor at EMI401 is burnt.  I can't make out the color bands, but the first one is green.  Available documentation suggests that this is a 1 Ohm resistor, though clearly mine is not.  The burned/scorched parts hide the colors of the other bands and I can't find anywhere that lists the resistor value for EMI 401 on my A500 rev 5 motherboard.  I suspect the value of the resistor is different on different revisions and I don't want to put the wrong value in there!

Anyone else have a rev 5 that could give me the color bands of EMI 401 ?  (It's near the JOYSTICK 2 port)

I'm guessing based on a few pictures available (all hard to read, sadly) that it's GREEN-BROWN-SILVER-GOLD or something close to that, which suggests 0.51 Ohm.

According to the service manual, EMI401 is a noise filter listed as 100pf. On the actual schematic, its drawn as a resistor with an extra lead going to ground... I'm assuming that's a 100pf capacitor to ground. It says 4.7 next to it, but no multiplier... In any case, the 5v to both joystick ports goes through it, so if you've got the 5v on the ports, I'd say EMI401 is OK.