Mouse stops working intermittently, but it's not the mouse

I have a 450 mHz G4 desktop running 10.4.11 and I'm having the worst problem with the mouse not working. I can sometimes get it to work again by unplugging the USB connection and replugging it back in. Thinking it was a bad mouse, I swapped out a known working mouse and keyboard and got the same results. So I thought maybe the USB port was bad, so I installed a USB card that I had from my G3, which also ended up doing the same thing. Is this an internal h/w issue, s/w? I have no clue what to do next. I have a similar machine that I use for parts in the basement, but I'm not sure what to try replacing if it is a h/w issue. Are there logs I can check that might tell me what's going on? Is there a h/w check to do?

450 mHz G4, Mac OS X (10.4.1)

Posted on Jul 16, 2009 5:46 AM

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23 replies

Jul 16, 2009 8:25 AM in response to Patrick Besong

Hello ( well lets see if two Patricks can make a right )

I also have the Power mac G4 desktop 466 MHz OS 10.4.11 digital/audio version that I bought used last fall. Just got it working to the Internet with a modem that I pulled from a G4 Quicksilver that has OS 9.2. I am learning about my Macs as i proceed here. Though i am in classes for computer tech, the practices are for the PC. I was hoping that Mac's would not have problems.

I thought I should at least come forward and present i have the same mac. ( maybe ) Anyway, here is my guess, have you tired connecting a USB HUB into the usb and watching how the pointer works? Otherwise, connecting other USB devices where you connect your pointer. Cause I see you replaced the USB card.

Then as i recall from my computer OS lessons, that there are these little drivers that can go bad. Correct me someone if I am out there in the Dark, But if PC's have drivers then I am sure the mac as drivers.

Is it possible that the drivers have become a bit worn and need to be updated?

My angle right now because i am in a software mode with my classes, am going to suggest the software

it is possible the exchanged USB card could produce the same result?

Myself I end up replacing the simple things first, I also wonder if the power supply could play a part. How about the computer environment?

And if you have a chance to hook up a wireless pointer ?

( Oh yeah I don't know what society's obsession with rodents is about, but its time to take the use of computers out of the play pin ) Its a pointing device !

Thanks

Patrick

Jul 17, 2009 6:36 AM in response to Patrick Besong

Patrick B,

When the mouse stops working, what exactly happens? Does the cursor freeze in one spot or does the cursor disappear?

I assume it's an optical mouse with an LED or laser rather than a roller ball? If so, when the mouse freezes, is the light on the bottom of the mouse still lit (probably red), or does it go out?

When the mouse quits, does the keyboard still work? I'd also be curious to know if the Caps Lock light on the keyboard goes out when the mouse quits.

I am troubleshooting a similar problem.

Jul 17, 2009 6:43 AM in response to Gary Wright4

The cursor freezes in one spot. The mouse is optical. I believe the light does go out, but I can't remember for sure. My wife uses that computer all the time. I'll ask her. I'm not sure if the keyboard goes out as well, but I believe it does. The only thing that seems to bring it back is unplugging the USB connection and plugging it back in. But that sometimes doesn't work either. Yesterday when I started the computer the cursor was frozen from the get-go.

Jul 17, 2009 8:06 AM in response to Patrick Besong

Sounds like you and I are working on the same problem. In my case the cursor freezes in one spot, and the keyboard does not work either.

Because the mouse LED goes out, as well as the Caps Lock light on my keyboard, it appears that the USB bus does not have any power after the freeze. This may be the root cause, or a symptom resulting from some other cause.

Like you, I get the same result from both the factory USB ports as well as the USB ports on my Belkin USB 2 card (PCI).

So far, a push-button power down and restart has always restored function for me. It's good to learn that unplugging the USB sometimes works.

I am still investigating to determine if this is a software problem or a hardware problem. Things I plan to try (but have not yet done) are:

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Hardware
With computer unplugged, check all connections from power supply to boards. (I hope to discover which line delivers USB power, and if the same line supplies both the factory ports and the PCI bus).

Check connections between all external USB devices, and replacing any cables that look cheap or damaged.

Reset PRAM

Reset PMU.

Run Apple Hardware Test disk. In my case, I have upgraded the CPU, video card and hard drive to non-Apple hardware, so I doubt this test will be very helpful.

Replace logic board.
(Note: I would generally replace the power supply before the logic board, but in my case I installed a new power supply about a year ago.)

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Software
Run Diskwarrior (I will have to buy it).

Archive and re-install system software.

Clean install system software.
-----

I plan to try them in the order listed.

Please post back if you find a solution, and I will do the same.

Jul 18, 2009 3:23 PM in response to Gary Wright4

Here's a handy place for all pin outs of all connectors including USB:

http://www.allpinouts.org/index.php/Main_Page

Apple's USB has always been under powered. Always use a powered hub and not one that uses the inline power.

The Mac usually gives you a warning if USB power drain is excessive. Also, to exclude your software from the mix, boot up off an Ubuntu live CD and see if the mouse hangs. You can also check out Ubuntu to see if you like it. 🙂

Jul 18, 2009 9:35 PM in response to motsteve

So what kind of 'warning' would I expect if my USB power supply was exceeded?

Would a cursor freeze/system freeze be typical if USB power demand exceeded supply?

I'm not using any kind of external USB hub; all my devices are connected directly to a USB port - either to the factory ports on the back of the Mac, or to a PCI card which supplies 4 external USB ports, and one internal.

Per System Profiler - here is what I've got connected:
Built in USB
- Keyboard (Apple aluminum) - nothing plugged into my keyboard ports
- Logitech receiver for wireless mouse - also plugged into 120V AC

Belkin 5 port USB 2 card (PCI)
- APC Back UPS - also plugged into 120AC
- Griffin iMic USB audio converter - sometimes used to connect headphones
- Canon i860 ink jet printer (normally off) - also plugged into 120V AC
- USB 2 cable - normally nothing connected - occasionally used to sync iPod Shuffle

Can I assume all items which are plugged into 120 volt AC outlets do not draw any power from the USB bus?

If so, that leaves only the keyboard and the iMic - and occasionally an iPod Shuffle. Maybe the Belkin card, itself, has some overhead, but I'm guessing the keyboard, the iMic, and the PCI card all together don't draw much power - they are all solid state (no moving parts), and nothing gets hot (at least not the keyboard or iMic - I haven't tried fingering the PCI card).

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When you say 'Apple's USB has always been underpowered' - do you have any numbers? Specs for the two factory ports are 500 mA, each - or one amp, total. What I don't know is how my PCI based USB 2 card gets it's power. The card specs say it provides 500 mA to each of it's 5 ports, but if Apple's power supply provides only 1 amp at 5 volts, then the PCI card can't very well deliver an additional 2.5 amps, can it? On the other hand, if the PCI bus has it's own 5 volt supply (independent from the factory USB ports), it might very well add 2.5 amps of USB power.

The fact that when 'frozen' - neither the factory USB port, nor the PCI USB ports will light the mouse's LED makes me suspect they both get their power from the same wire - yes? no?

-----

The link for pin-outs looks like it might be useful, but I found that site to be difficult to search, and gave up before I found anything specific to my model. This link has a pretty good diagram:
http://www.xlr8yourmac.com/tips/MDDps_mods/MDD_PSMods.html

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I am using a 3rd party shareware to configure my Logitech wireless mouse (SteerMouse from Plentycom) - would my mouse even work under Ubuntu?

I may go a week or more between freezes, so testing is going to be slow.

Jul 19, 2009 3:31 AM in response to Gary Wright4

The warning I always got was "Device on buss exceeding 500mA current drain" or some such warning. I didn't have that for real, but I usually was able to get it to go away by changing my buss configuration and restarting. The only time I've had hangs was due to the software. Try powering up in the safe mode and see if it still does it or boot off of another drive with a working system on it. Push comes to shove you can also strip everything down to keyboard, mouse and that's it for the bus.

You did mention your PRAM. When was the last time you checked the back up battery? This is definitely pertinent if you have had your Mac unplugged for a while lately. When the Mac is off line, the pmu is only kept alive by the back up battery. Resetting with a dying battery will sometimes fix a problem, but only for a short while. A good place for battery replacements is OWC. see:

http://eshop.macsales.com/Search/Search.cfm?Ntt=pram%20battery&Ntk=Primary&N=0&N s=P_Popularity

Jul 20, 2009 4:44 AM in response to motsteve

I have tried Safe Boot several times.

Because the freeze prevents the normal methods of shutting down, I've been pushing the power button to shut down. I always start up in Safe Mode after a push-button shut down. However, I have not tried actually using the computer in Safe Mode for any length of time because lack of access to all my 3rd party stuff cripples my ability to get anything done. I may go a week or more between freezes, so for me, that would be a long time to suffer with Safe Mode's limited capabilities.

My back up battery is just about exactly one year old. For me, the freeze has never occurred at start up - which is where I would expect to see problems due to a failing back up battery. Patrick reports an occasional freeze at start up, but I don't believe that is typical for him, either. I do plan to replace the battery next time I have the Mac unplugged, just in case.

It seems to me, the hardware vs software is the key question. And the fact that the USB bus does not have power after freezing is a big clue, if I could only figure out what it means. If there is a continuous circuit from the power supply to the USB bus (note: 'if') - then how can software affect that?

Possibilities:
- A bad power supply quits putting out 5V power to the USB bus, causing the freeze.
- A connection between the power supply and the USB bus is failing, causing the freeze.
- Some kind of software is telling the power supply to quit supplying USB power

Is there any other possible explanation for loss of power at the USB ports?

Jul 21, 2009 5:34 AM in response to Gary Wright4

If you have a bootable copy of your normal startup disk and that acts the same way, then all I can say is that you could start subtracting or disabling the third party software until you get stable results. I don't know how the USB power is controlled by the OS, but the fact that you can operate under safe mode does point a big finger at software and not hardware.

I just now fired up my DA from a cold start and the bus didn't light up until the self test was done (chimes sounded) and it started through the normal hardware scan ending up in the OF boot procedures (I have my Mac set up for dual boot Mac/Ubuntu using yaboot). After the OS starts, I really don't know if anything could occur that would cause the OS to unpower the USB. The only other thing I can think of is that there is a conflict on the bus between your mouse and another device that is trying to do the same function such as you would have with a tablet. I'm sorry that I can't be of more help here.

Jul 25, 2009 5:58 AM in response to Patrick Besong

Hi, Patrick -

I had similar problems several years ago; fried a keyboard in the process.

I came across Apple KBase Article #TA26015 - Apple Pro Keyboard: Devices Connected, which led me to believe that the optical mouse was overloading the keyboard's ability to pass sufficient power to the mouse. I changed my USB config so that the mouse was plugged into a port other than the keyboard, and the problem disappeared.

At the time I had a monitor with a built-in powered USB hub, so I used that for the mouse. I've since replaced that monitor with one that does not have a USB hub; since I have no other USB devices, I now use the second port on the back of the G4 for the mouse.

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Mouse stops working intermittently, but it's not the mouse

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