[dynaflux]

I have a iBook G4, 14", 1,33 MHz that won't start and it's not the usual bad soldering joint on the ISL 6225CA - those will I manage to fix. I have also tried to solder this one.

When I press the start button the fan will not start running, and the screen stays black. The HD is spinning but I can't hear it working. It's possible to toogle the Caps lock.

There's a high frequent sound (not loud) from the CPU area, however I'm not sure it´s from the CPU itself as it is hard to pinpoint exactly.

Have anyone encountered this and have a suggestion what to do?

[Sherman Homan]

So it spins the hard drive, and the cap locks light turns on? When you say that you tried to solder this one, what happened? When you try to power it on, does it make any sound, chime, beep?

[dynaflux]

The HD spins. Caps lock don't go on when I start but ist is possible to activate/inactivate (i.e. the LED goes on/off).

Soldering didn't change a thing - no start sound, nothing.

[Sherman Homan]

Will it boot into Target mode? Single User mode? Probably not if there is no chime, (but that could be something like speaker wires or the volume turned off!) I think you are the proud owner of a blown CPU.

[dynaflux]

I'm not that good at OS X (just hardware)... how do I boot into target mode or single user mode?
It's worth a try but I strongly suspect a hardware issue. I might even be a proud owner of a blown CPU. Arrghh!

[Sherman Homan]

First, try Open Firmware, restart, immediately hold down the following four keys:
Command Option O F
Type in:
reset-nvram (press the enter key)
reset-all (press the enter key)
reboot

Single User mode - startup, hold down Command and the letter 's'.
/sbin/fsck -fy
repeat if system is modified,
reboot

Target mode - startup, immediately hold down the letter 't'. Hopefully you will rewarded with a screen with a bouncing Firewire logo. This may allow you to recover files on your hard drive, isn't much good for anything else.
Best!

[dimmer]

If you can solder surface mount technology (SMT) parts you are a genius. Of course, if the resulting system won't start you've just messed up your warranty and any hope of assistance.

[dynaflux]

I have made some success with a heatgun on the BGA-mounted GPU on some G3:s. I have also soldered many Intersils on G4 but I don't know if you have to be a genius. However you need a small solder tip, a magnifier glass and a very steady hand.

Have you any suggestion on which parts that can need resoldering/reflowing on a G4?

There is no warranty and I have nothing to loose.