liquid damage:ibook G4 won't stay in sleep mode when power cable connected

Hi
I spilled tea on my ibook G4: and did the stuff you're meant to do, but not straight away. Did take off keyboard and mop up liquid, so yes there was quite a bit there.

What's happening now is that if the ibook is connected to power, it will not stay in sleep mode, either when I close the lid, or when I use the drop down menu. If its not connected, then it will go to sleep fine.

Other random keyboard stuff was happening with g and > getting stuck on, or not working. this then developed into other keyboard faults and eventually the Apple key not working properly either!

However after Christmas, I thought I would give things another go, so I unplugged the keyboard again and did a bit of cleaning around the power socket, as these keyboard problems seem to start after the power cable has been plugged in. I also cleaned around screws that hold ram shield in place as there was some black under them.

Well this seemed to have sorted it.....left it plugged in and for a quite a few hours all was good, but then this morning it was up to its old tricks, going to sleep and then waking itself up, and making itself rather warm in the process.
The keyboard glitch is now on the z, which goes between not working and printing loads of zs, much in the same style that the gs were doing.
As it is, it's usable: as long as it doesn't get any worse.......

I'm wondering is it worth doing a more thorough clean around the power socket? Or anywhere else?.....or any other advice please......