Testing for signs of life after liquid damage

Question

Hey all,
I picked up a Macbook from work yesterday (repairs department) that had been returned a month or so ago as being 'dead' but upon inspection (smelling the keyboard!) I realised coffee had been spilled on it. Long story short, the Macbook was sitting in its box since then in spite of the liquid damage so it's probably been beavering away down there messing things up. As I was, of course, not present when the liquid damage occurred, I've no way of knowing if the machine instantly turned off due to a short or maybe carried on running and was shut down and then after that refused to turn on, or if they were lying/misinformed when claiming it was dead.
Anyway, I've torn it down all the way to and including the keyboard, cleaning all the components along the way and everything looks in top-top condition now, albeit still taken apart.
There's only one problem:
The machine doesn't appear to turn on, but it does charge. Also, the battery indicator light works properly. However, the dvd drive does not make its startup mechanical noise, nor does the hard drive power up. The fan doesn't spin either, but I'm not sure if the fan only ever begins to spin when the temperature reaches a certain point. The led light on the front does not glow at all, either. According to the Apple site, if the system has no ram in it the led should blink once per second but it doesn't do that. I dunked the logic board in shallow rubbing alcohol last night and lightly scrubbed it with a soft toothbrush and left it to dry overnight and it looks clean now. I'm about to plug it back in to see if it starts but I was wondering:
*What are the minimum components needed to be present in a Macbook to check the logic board is functioning?*
With most PC laptops, they'll still turn on the hard drive/screen/etc without any ram or cpu installed but there'll be nothing onscreen, whereas I've come across others that will show absolutely no signs of life at all if the hard drive is set to slave when it should be master!
Do I need to have the screen, drives, and all other bits all fully connected to see if the machine will at least turn on? I'm worried the power button on the keyboard could be faulty but have no way to check that at this moment.
Thanks for any replies(as long as they're not about voiding warranties)!

Answer 1

Thanks for mentioning the hardware test, I didn't think about trying that (assuming I get it to boot), but did you read my post properly?
Probably not, so I'll summarise it (it was a bit wordy):
I have a Macbook that someone spilled coffee on. But in spite of completely disassembling it and cleaning all traces of coffee (isopropyl for circuitry, soapy water for everything else), it won't turn on at all. There is still some coffee inside the keyboard between the two layers, and I believe this coffee is the problem as the laptop charges the battery but won't turn on at all so I think the keyboard is not sending the power-on signal properly.
I was trying to find out *whether Macbooks can be turned on without having to reconnect all the parts* (monitor, ram, drives, etc) just so I know that it at least powers up. Since posting, I've now reassembled the entire Macbook except for the keyboard so I suppose it's largely moot. I'm thinking of buying a new keyboard from eBay to see if that will power up the machine. If it doesn't, then I'll give up.
The bit about warranties has become standard practice for me and was to stop people replying along the lines of "but you'll void your warranty" or giving their two pence about how they'd never EVER void their warranty. It's really annoying because it makes the poster sound silly, and only brings disappointment when I get an email and think I'm getting an answer.
I'd like to believe anyone with an ounce of intelligence knows when they're doing something that will void their warranty, and I seriously doubt there are many cases where someone has unknowingly voided their warranty by opening up or repairing something they shouldn't, only for someone to reply and show them the error of their ways before they realise!