I picked up a PB5300cs over the weekend, an eBay find. I should have taken "before" photos but didn't - the battery either leaked or there was some sort of electrolytic reaction as a good half of the case was covered in what looked like copper sulfate. Luckily, the motherboard and RAM card, HDD, video out card all seem unscathed except for some CuS on the metal shields. You can still see some that vinegar/lemon juice didn't get.
Pre-cleaning, the unit gave a reassuring PPC startup bong when power was connected and responded to control-option-power to reboot but the HDD didn't spin up and there was no other life.
So I disassembled and washed with lemon juice/vinegar, rinsed with de-ionized water and have allowed it to dry fully. The result is the same as before - bong but no other life. There is some white corrosion around where the battery/power daughterboard connector is, on the daugherboard (see photo) and I am awaiting delivery of PCB cleaner to try to shift that. All the capacitors seem OK. The PSU is putting out 24V (well, 23.8) so that seems OK. My theory is that the corrosion on the power board is causing the rest of the system to not get enough power... thoughts?
Any other tips as this is my first vintage Mac rescue? Does it matter if I have the PRAM battery connected and if it's dead?