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Strangest PowerMac hardware question - HELP!!!

gotohamish

gotohamish

macrumors 65816
Original poster
Jul 15, 2001
1,078
10
BKLN
Anyone know what THIS does on the PowerMac Mirror Door Dual 1.25Ghz PowerMac G4?

I just opened up the side, and a LaCie d2 hdd on top fell INTO the Mac, snapping it off the motherboard. The machine boots and works fine (so it seems)

powermac_part.jpg


The strange thing is, I was opening it to install a FW PCI card because the internal FW seemed to have died and was not registering at all in ASP, however, now it's working fine - and I didn't install the card!

Any ideas? HELP!

Thanks, H
 
got a pic of the other side and also a side view?
those would help to determine whether or not it's a battery like the previous poster suggested
 
thehuncamunca said:
got a pic of the other side and also a side view?
those would help to determine whether or not it's a battery like the previous poster suggested
Click to expand...

I'll take a couple, gimme a sec.
 
thehuncamunca said:
got a pic of the other side and also a side view?
those would help to determine whether or not it's a battery like the previous poster suggested
Click to expand...

Here are the pics you requested:

powermac_side.jpg
powermac_bottom.jpg


Does that help?

I'm trying to figure out where on the motherboard it was.
 
Its a capacitor.
Perhaps it failed shorted and "melted" itself off of the board.
You should be able to find where it came off. Possibly near the Firewire device.
The top of the can almost looks like it ruptured.
Now how to fix it... if everything works OK, perhaps just leave it.
If you experience "flakiness", it needs to be replaced and that is more involved.
 
Flynnstone said:
Its a capacitor.
Perhaps it failed shorted and "melted" itself off of the board.
You should be able to find where it came off. Possibly near the Firewire device.
The top of the can almost looks like it ruptured.
Now how to fix it... if everything works OK, perhaps just leave it.
If you experience "flakiness", it needs to be replaced and that is more involved.
Click to expand...

It's dented. Good and proper, due to a big Lacie External crashing down onto it!

What is it related to?

I appreciate your help.
 
Passante said:
I'll open my G4 and see if I can find that capacitor on the motherboard.
Click to expand...

Thanks all - so does anyone know what this particular capacitor actually does?
 
gotohamish said:
Anyone know what THIS does on the PowerMac Mirror Door Dual 1.25Ghz PowerMac G4?

I just opened up the side, and a LaCie d2 hdd on top fell INTO the Mac, snapping it off the motherboard. The machine boots and works fine (so it seems)

powermac_part.jpg


The strange thing is, I was opening it to install a FW PCI card because the internal FW seemed to have died and was not registering at all in ASP, however, now it's working fine - and I didn't install the card!

Any ideas? HELP!

Thanks, H
Click to expand...

I'm pretty sure that its come off the graphics card, take it out and have a look, you should see a white circle where it would have sat, if you can solder or if you know of somebody who can, put it back on, its there for a reason.

Alex
 
Its the flux capacitor, you're screwed.

But really folks, it does look like a capacitor. Capacitor's are a reservoir to store energy in case a particular part of the circuit needs a boost of energy. If nothin is awry right away, then everything will probably work out fine. Maybe slight degredation in redraw rate if it is part of the graphics card.
 
use low power mode

GimmeSlack12 said:
Its the flux capacitor, you're screwed.

But really folks, it does look like a capacitor. Capacitor's are a reservoir to store energy in case a particular part of the circuit needs a boost of energy. If nothin is awry right away, then everything will probably work out fine. Maybe slight degredation in redraw rate if it is part of the graphics card.
Click to expand...


If your computer/video card reachs anything near 1.21 gigawatts.... you may get a time out error! :eek:
 
Capacitor...

Thats quite interesting, thats a Cap rated at 16volts, one would assume thats working on a 12v rail.

We de-rate components, so we use a higher spec component for the job its doing, in order to ensure it isn't running at 100% stress (thats bad, reduces expected life of component). Its interesting to find that Apple work on a minimum of a 75% de-rating, i de-rate at 70% for e-caps at work for all our projects....in other words ppl, i wouldn't let your macs run hotter than they need to!

I agree with letting the mac run should you not have any issues with it - but that component was there for a reason, Apple Engineers wouldnt put a cap there for decoration! Find out where it came from, and see if there are any issues with that area of the Mac.

FireArse
 
It's a 470 microFarad electrolytic capacitor, rated at 16 volts!
Probably on a 5 or 12 volt power rail.
It doesn't appear damaged - the dented cross on the top is part of the manufacturing process!
If you plan on replacing it, you might be better off buying a new one, with long leads, as it may
be a bit tricky to resolder a surface mount component.
A replacement should be available from your local electronics store for about 50 cents!
You may find everything works OK about 95% of the time - but best replace it for the other 5%
Make sure you get the +ve and -ve connections correct if you replace it!!!!

Good Luck :)
 
It's fairly likely that it's just a bypass capacitor for one of the power rails. 470 uF at 16 V is not an uncommon value at all, replacing it should be easy. If you can't do it, find an electrical engineer friend or someone who's got experience with electronics. They should be able to do it for you without much trouble or time.
 
MacTruck said:
Open the case about an inch and drop that sucker back in there. Close the case and forget it ever happened.
Click to expand...

hahaha! That's great advice-- that's exactly what I would've done.... haha
 
Kaver said:
Make sure you get the +ve and -ve connections correct if you replace it!!!!
Click to expand...
Otherwise it would really blow up (and possibly ruin something else)!!! You gotta be very careful with electrolytic capacitors.
 
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