Hardware replacement to fix not-working MacBook keys 1 1/2 weeks ago I had the glorious idea to clean the keyboard of my white MacBook Mid2010 with a wet cloth. Now, several keys are not working anymore, and I guess there might be a close-circuit hardware issue.

When the MacBook is open, I cannot enter the sleep mode, since it awakes itself immediately. So, I am using my MacBook for almost 2 weeks as a home computer now: keeping it closed, hooked up to a screen with bluetooth mouse and keyboard.

Right now I cannot afford it to send it to Apple, because I am authoring a book that is due end of April. But immediately after this is done, I might want to send in my MacBook to Apple to get it fixed.

Now, I am wondering if someone had similar issues and sent it to Apple? It would be interesting how long such a repair might take (within a week?) and how much it approx. would cost? Because maybe it's not worth repairing this Mid 2010 MacBook, and maybe I should get a used MacBookPro instead?
Most repairs in retail stores are for less than 5 days - and more than half the repairs are done in less than 24 hours. 

There are some bad signs in the symptoms you mention. Sleep sensor failing is often liquid damage. Keyboard keys failing is also often liquid damage. Even if it's not liquid damage, the logic board or keyboard and some other parts would need to be exchanged and the keyboard is part of the unibody frame, so basically it's like taking a car in for a new frame. All the old seats, engine, power train, etc… get hand removed, inspected and re-assembled in the new chassis. It's not that bad, but it's a lot more time consuming than just putting in a fan or a battery or hard drive in. Those take 20 minutes tops.

So, as you mention - finish your work, keep good backups and then send it in knowing it's likely to be $150 to $320 to fix (in the USA presumably) and if there is liquid, you should probably sell it for parts, since the repair cost will jump to $800 or so.