MacBook Pro - No Power in, Stalled boot-up from battery

[anvilhoister]

My MacBook Pro 15.4, 2.4Ghz slowly drained the battery while still connected to the mains, went to sleep and wouldn't restart. No light on the charger magsafe plug so bought a new charger.

Made no difference so bought replacement battery. MacBook started up, chime, fans, log in screen then died. Removed new battery and restarted with same result only less time between starting and it cutting out. Still no light on the charger Magsafe plug.

Replaced the DC in Board with a new one and tried again. Same problem with the time between switching on and it shutting down now only a matter of a second or two difference. Still no light on the Magsafe charger and no idea where the problem may lie.

It can't be the logic board can it? It was working fine until it stopped taking a charge and booted to the log in screen with the new battery.

I think its a power regulation issue somewhere but haven't a clue where.

I've reset the ( SMC ) Systems Management Controller by holding down the power button for 5 seconds but it made no difference.

Any ideas??

[SGilbert]

The only board left is the DC to DC board. If you replaced the DC in board, and you are sure it isn't the logic board, that's all that is left.

[anvilhoister]

Many Thanks, I'll check it out.

[anvilhoister]

Originally Posted by SGilbert

The only board left is the DC to DC board. If you replaced the DC in board, and you are sure it isn't the logic board, that's all that is left.

Hi,

Can't find any reference to the DC-DC board that you suggested may be the cause of the problem. Can't find it listed as a replaceable part. Suspect that its soldered to the main board. Is this the case and if so where? How can I recognise it?

Thanks.

[SGilbert]

They're all different, and I only suggested the DC to DC board as That was the cause in a relatives 12" Aluminum G4 Powerbook. You MAY not have it, or it's part of the Logic board.