First off, thanks for a wonderful website & community. Secondly, I'll try to keep it short. But I'll fail. So a couple of...

The method that worked for me was described by Saul123 on August 5, 2007. I have previously tried every other solution I could find and nothing worked (i.e. putting device to DFU mode didn't work), the device was not being detected by PC or Mac. The trick described by Saul123 helped me to revive iPod Classic 5th Generation 60GB that's been sitting for 10+ years, I even didn't have to swap the battery. In case the link to original post stops working, here's what I did: (1) I hooked up my iPod Classic 5th Generation 60GB to Apple 20W wall charger via Apple 30-pin cable. (2) I pressed MENU+PLAY buttons simultaneously for ±10 sec until the Apple logo appeared on screen. (3) I released MENU+PLAY buttons for split-second while Apple logo was still on screen. (4) I kept repeating steps 2 & 3 in a loop for about 5-6 times. (5) On the 3rd time I felt the HDD started spinning, but I kept repeating the 2&3 steps loop. (6) I released all buttons after 5th-6th loop. iPod Classic then displayed full-color black screen...

Sorry I never made it to respond earlier. It's been a while. After taking my MBP to another service they promised to test it with a working battery. They never did (couldn't find a proper replacement). Since I had to be doing my engineering work to get paid I decided to sell MBP later as is in case I never have time to order a replacement battery. Poor service in my city would be waste of time (and they could damage logic board while replacing ISL6258A). Obviously I continued working with MBP hooked to power source 24/7 for next 6 months. I ended up selling it for $1000 as is and buying top configuration MBP with Retina display in August, 2012. Summarizing this thread if you happen to liquid-damage your MBP and have same symptoms afterwards (after cleaning MBP interior with spirit, praying, etc.) your best bet is replace battery. In case this won't help try replacing ISL6258A (requires soldering equipment and skills). Your last chance before replacing logic board will likely be replacing DC-in. Good luck!