Battery "replace now" is showing up but this is definitely wrong!

Hi guys,

I am a little bit frustrated with my MBP. To tell the complete story first: After some liquid spills that did not damage anything but the keyboard I was annoyed from keys not working properly. As this model still has got the holes drilled in to remount a new keyboard I decided to go for a replacement. I ordered a keyboard from one company and went to a store close to my house to have them replace the keyboard. I did share all information with them on the first hand and they were happy to do this for me. BTW, I am German and from Germany. At this point the MBP was just having some keys not working proper (but even those did work, no other problem!).

Well, after 7 hours (he said: "will take 2hrs") I went to the store. He said he was too busy, I should come again next day. They called me later to say that the keyboard I bought seems to be defective and that they cannot repair my MBP. I was angry but did pay for the replacement (w/o parts as they wanted to charge me 3x the price I paid at the other place). So I could not insist that they have to fix it, though.

I went off with my MBP w/o the keyboard (which they had to ripp off the top case), returned home, switched on the lights and started disassembling the MBP. I screwed in the new keyboard and reconnected everything. I used ifixit and youtube in parallel not to miss anything.

At the end I have a MBP with a new and perfectly working keyboard, almost everything is perfect BUT the battery. The battery is recognized, fully charged, MagSafe ist green and CocoNut is showing all the SMC data. But the MBP does neither power up on battery nor does it stay on when unplugging it; the MBP does turn off instandly.

The battery is 24 months "new", has a rest of 8223mAh (coming from 8440, so almost 100% still). There were no problems whatsoever before I went to see that "specialist" or "professional". For me it looks like the power management can communicate to the SMC and can read the voltage from the cells but the current does not go to the logic board, though. Is there any thing like a fuse I can check? Terminals I can measure at?

ANY HELP is appreciated!!!

Thank you folks.

Thorsten