So I recently picked up a PowerBook G4 at a flea market for $4. I thought it was interesting to play around with a mac, because I've never done it before (I'm mostly familiar with Windows and x86 stuff). The laptop came without battery, power adapter, RAM and hard drive .
The problem is that I can't get it to POST (I hear 3 beeps and see the front light blink accordingly). I tried all my RAM sticks (PC2700) without any luck. I've heard that for these machines it's notoriously hard to upgrade the RAM.

I have to specify that I modded the power connector with a standard barrel jack, because it's almost impossible to find working Apple power adapters in my area. Even though I think I've done a very good job soldering it, I haven't added that 0.5M resistor thing because I wasn't sure about it (could that be at fault?).

Can anyone give me advice on how to troubleshoot this laptop ?