Chosen Solution
Came back from a coffe break and found my Mac continuously rebooting by itself. Ended up taking off the hard disk data in target mode to another computer, but would frally like to fix this one! Here are the symptoms, does this sound like the type of problems that the 2011 model was having back then? WITH BATTERY CONNECTED: Battery shows OK when battery tested (third party software) Magsafe light shows green (strange though, always green) But if the magsafe charger is taken off while computer is on, screen (& computer) goes immediately black. During boot up, screen goes black soon after the login box is filled in, immediately after the appearance of a series of warning boxes (date & time not set and allow or deny boxes for several processes like cups, smbd, applefileshare, k5bxxx). As said, the screen then blacks out and the computer starts the boot process again, unless I shut it down at the login box stage. PRAM and SMC were reset without any resulting change. I also installed a new magsafe DC i/o in (thank you iFixit for the procedure!) but it didn’t seem to make a difference, although it seems like the computer gets farther in the boot process with the battery installed than it did earlier (repeated boot cycles often before getting to the login box) WITH BATTERY DISCONNECTED: With battery disconnected, boot process finishes but the computer does not keep time/date etc (things controlled by SMC) the next time, if the charger is ever taken off, even just for a few seconds, when the computer is off. When the computer is off, just attaching the magsafe charging cable initiates a boot chime, sometimes even when the screen is closed. Then, without pressing the start button at all, the computer goes through 1 to 3 chime cycles before the apple screen appears (almost like a PRAM reset) and the machine then boots to completion. Whole computer seems to lag. Long boot up time, takes a couple of minutes before the USB mouse starts reacting, sometimes also same thing with the trackpad and keyboard, activates only after a couple of minutes. Anyone have any ideas if it is the logic board or ??? Thanks!
The issue is most likely your battery :)If battery is not connected, it is not going to keep the date and time, and you will always have to adjust it after you unplug or restart the computer. There is a slight chance that your logic-board cannot charge the battery also, but I would say it is most likely your battery that needs replacement. You can get a battery and replace it and see if it fixes your issue, make sure you can return the battery you buy just in case its the logic-board :)Let me know how it goes.Macbook Repair is tough but diagnostics is 95% of the way.
