Looking for a second opinion:

Powerbook G4 550 (non-DVI)
No backlight when turning on the computer.
When waking out of sleep, backlight comes on full force, there is a
noise from the RH speaker, then the backlight turns off. Brightness
controls (key or software) have no effect.

Have done the PMU reset many times; PMU is obviously reset by observing
the clock.

Any actual experience with this problem and the repair?

On Tue, 4 Nov 2003 10:53:50 -0800, gregory trimper wrote
(in message <2BSpb.8918$Oo4.396@newsread1.news.atl.earthlink.n et>):

> Looking for a second opinion:
>
> Powerbook G4 550 (non-DVI)
> No backlight when turning on the computer.
> When waking out of sleep, backlight comes on full force, there is a
> noise from the RH speaker, then the backlight turns off. Brightness
> controls (key or software) have no effect.
>
> Have done the PMU reset many times; PMU is obviously reset by observing
> the clock.
>
> Any actual experience with this problem and the repair?
>

Did you do a Hardware Test using the OE disks, or any third party utilities
disks?

X-No-Archive: Yes

Steve wrote:

> Did you do a Hardware Test using the OE disks, or any third party utilities
> disks?

Of course, and both TechTool and AHD report no problems.

GTr

On Thu, 6 Nov 2003 7:44:49 -0800, gregory trimper wrote
(in message <R%tqb.12602$Oo4.6190@newsread1.news.atl.earthlink .net>):

> X-No-Archive: Yes
>
> Steve wrote:
>
>> Did you do a Hardware Test using the OE disks, or any third party
>> utilities
>> disks?
>
> Of course, and both TechTool and AHD report no problems.
>
> GTr
>

Then I would suspect a software issue. Were it my machine I would back up ALL
data and re-format the HD and re-install.

Steve wrote:

> Then I would suspect a software issue. Were it my machine I would back up ALL
> data and re-format the HD and re-install.

No. Not only does booting from the AHD CD eliminate any software issue,
the multiple PMU resets eliminate that as well.

It is an obvious hardware problem, and I'm fairly sure it is the
inverter, but was wondering if/fishing for any authoritative experience
with, perhaps, a bad PMU causing the same symptons.

GTr