Mac Forums

Mac Forums (
-   Apple Desktops (
-   -   Just swapped imac G5 logic board, now no USB or IR keyboard/mouse function (

Jenn 03-09-2011 03:40 AM

Just swapped imac G5 logic board, now no USB or IR keyboard/mouse function
Hey all-

My dad's capacitors burst, giving him crazy video issues and then kernel panic. So I bought him a parts imac on Craigslist with a supposedly good logic board. I just swapped it out and everything went well, but his IR keyboard won't work, and neither will his USB mouse.

Any ideas? Something I screwed up during the swap? Just another bad logic board? Any tests or workarounds?



thewk 03-09-2011 11:05 AM

Are you sure that the motherboard you bought was correct type? Also when it was installed, did you make sure there are no short circuits, that it is in place perfrectly and no screws etc are touching the backside of the board? Does keyboard and/or mouse lights lit when you power up the machine? Can you get into open firmware by powering up the machine and immediately pressing CMD, ALT, O ja P keys together at the same time? If it does get you to open firmware then USB-ports are working but there is something wrong with OS X. Try doing PRAM-reset by pressing CMD, ALT, P and R -keys at the same time right after you have pressed power button, you should heat loud noise and probably see the sleep led flashing, after you hear the chime second time you can let it to boot normally.

I personally would have changed the cap/caps since motherboards tend to be expensive....

Jenn 03-09-2011 09:40 PM

It's definitely the right board, your idea re: screws etc touching the reverse of the LB is a good one; my best hope at this point!

Neither the keyboard nor mouse lights up when it's plugged in.

I haven't yet tried the specific keystrokes you suggest (I'm still at work), but I look forward to trying. I did try to start up in safe mode, and in target disk mode, but neither had any effect. Even plugging my iphone headphones into the jack didn't silence the startup jong noise.

Thanks for the ideas. I'm gonna dive back in hoping to find a short.

Wish me luck!


Jenn 03-10-2011 02:33 PM

(Sorry for the B2B)

My laser mouse gets power from the imac (but doesn't work), but NO startup keystrokes work:

target disk mode
safe mode
select startup folder

Any ideas?



The wireless (IR? BT?) keyboard won't work either. Might there be some sort of sw conflict involving that?

Damsel in distress over here!

All times are GMT -4. The time now is 04:48 PM.

Powered by vBulletin
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.