Repairing Midplane on G5 iMac

I'm about to embark on an adventure and was wondering if anyone has had
any experience with this.

I bought one of the original G5 iMacs back in November 2004. It has had
the power supply replaced and the mid plane replaced twice due to
faulty capacitors. The bad capacitors were easy to identify due to the
marking on the top surface and, when I got the second replacement back,
I looked inside and found three suspicious capacitors. Now, a year
later, those three capacitors are bulging and leaking. A call to Apple
confirmed what I had suspected: the Extended Repair Program for this
failure ended last November (for me at least, being three years) and
there was simply nothing they could do for me. I'm not sure what
"extended" means as it is no lengthier than the Apple Care warranty.

So, since my original warranty, Apple Care, and the Extended Repair
Program have all lapsed, my only choices are to have someone install a
new midplane board or try to replace the capacitors myself. I noticed
that the price for the midplane board was $780 the last time I had it
replaced, so I'm not really considering that option. I suppose I could
pay the repair shop to replace the capacitors (Alpha Computer in
Richland WA, if you're out there reading this, Mindy), but I expect the
bill would also be pretty hefty.

Being an electrical engineer, I have no qualms about pulling the board
and replacing the capacitors. I assume that they are commonly available
electrolytics and shouldn't be hard to find. I also have the 45-page
document from Apple describing the board replacement process (from when
this was considered to be a fix-it-yourself machine).

Has anyone performed this procedure? Any hints or tips to pass along?

Also, I know that the inverter is not 100% (bright bar along the bottom
of the screen and buzzing since day one) but it was never bad enough to
get covered by the repair program. Does anyone know of a source for a
661-3623?

Wish me luck...
--
Bream Rockmetteller
Donaldson's Dog Joy
509-450-0301

On 24 Feb, 19:48, Bream Rockmetteller
<bream(dot)rockmetteller(at)mac(dot)com> wrote:
> I'm about to embark on an adventure and was wondering if anyone has had
> any experience with this.
>
> I bought one of the original G5 iMacs back in November 2004. It has had
> the power supply replaced and the mid plane replaced twice due to
> faulty capacitors. The bad capacitors were easy to identify due to the
> marking on the top surface and, when I got the second replacement back,
> I looked inside and found three suspicious capacitors. Now, a year
> later, those three capacitors are bulging and leaking. A call to Apple
> confirmed what I had suspected: the Extended Repair Program for this
> failure ended last November (for me at least, being three years) and
> there was simply nothing they could do for me. I'm not sure what
> "extended" means as it is no lengthier than the Apple Care warranty.
>
> So, since my original warranty, Apple Care, and the Extended Repair
> Program have all lapsed, my only choices are to have someone install a
> new midplane board or try to replace the capacitors myself. I noticed
> that the price for the midplane board was $780 the last time I had it
> replaced, so I'm not really considering that option. I suppose I could
> pay the repair shop to replace the capacitors (Alpha Computer in
> Richland WA, if you're out there reading this, Mindy), but I expect the
> bill would also be pretty hefty.
>
> Being an electrical engineer, I have no qualms about pulling the board
> and replacing the capacitors. I assume that they are commonly available
> electrolytics and shouldn't be hard to find. I also have the 45-page
> document from Apple describing the board replacement process (from when
> this was considered to be a fix-it-yourself machine).
>
> Has anyone performed this procedure? Any hints or tips to pass along?
>
> Also, I know that the inverter is not 100% (bright bar along the bottom
> of the screen and buzzing since day one) but it was never bad enough to
> get covered by the repair program. Does anyone know of a source for a
> 661-3623?
>
> Wish me luck...
> --
> Bream Rockmetteller
> Donaldson's Dog Joy
> 509-450-0301

this is probably obvious, but i remember thinking "why on earth didn't
i think of that?" when I first heard it...

if you're replacing dodgy capacitors on a motherboard, don't mess
about trying to unsolder surface mount stuff. instead, grip the cap
firmly with pliers and pull it off vertically: you should end up with
the soldered legs remaining firmly attached to the motherboard, and
the cap itself lifting off cleanly. solder the new cap to the
existing legs. this is much easier than trying to solder to
motherboard traces and removes the risk of heat damage to the board.

you might want to practice this on some dead hardware the first time,
though!
ric